Sometimes conversations involve people using the same word differently. In the best case scenario, participants notice and choose a favorable provisional definition. Outside of conversations, people advocate for specific meanings to be adopted or not adopted more broadly. Below, I discuss reasonable and unreasonable ways people evaluate definitions, along with examples.
Good ways to evaluate a definition
Good reason
Why good?
Example
Practical applications
Some words’ and phrases’ definitions have practical applications
Scientists recommending that cancer 10–15 cm from the anal verge be defined as colon cancer rather than rectal cancer because it seems to respond to additional chemotherapy, which is also the case for colon cancer (Swets et al. 2017)
Scientists recommending that the definition of statistical significance be changed to p < 0.005 because it would help improve reproducibility (Benjamin et al. 2018)
Common usage
We use words to communicate with others; they have to understand us
An editor recommending that the term chips not be used to mean what Americans call French fries for an article with a global audience
A friend recommending that violence refer to acts causing physical damage for the duration of a conversation, since this is a common usage and is more intuitive than inclusion of mental damage
Standardization
It’s easier to communicate when there are commonly accepted definitions of words
Scientists recommending a more standardized definition of ecological terms like community in order to create more understanding (Stroud et al. 2015)
Factual correctness
Some words and phrases, especially scientific ones, are defined by the characteristics we’ve observed about them
Electricity changing in meaning from “The operations of a very subtil fluid, which appears to be diffused through most bodies, remarkable for the rapidity of its motion, and one of the most powerful agents in nature…” in 1828 (Webster) to “a fundamental form of energy observable in positive and negative forms that occurs naturally (as in lightning) or is produced (as in a generator) and that is expressed in terms of the movement and interaction of electrons” in 2026 (Merriam-Webster)
Carving nature at its joints
Words for categories are more useful if they reflect meaningful distinctions
Astronomers formally defining planet in 2006. One of the new criteria was whether an object has “cleared the neighborhood,” referring to whether it gravitationally dominates its orbital region. On measures of this property, the eight planets are separated from Pluto and other dwarf planets by a large gap. Although choosing where to draw a category boundary involves some arbitrariness, the definition tracks a substantial physical distinction among objects in the Solar System
Consistency with rules of the language
Languages can be made easier to learn
Recommending a similar use of hopefully to other adverbs. Historically, hopefully referred to doing something with hope, as in “Hopefully, he asked for a raise,” but now often expresses a desired outcome, as in “Hopefully, I get a raise.” This example is from The Sense of Style by Steven Pinker, where he notes that “many adverbs, such as candidly, frankly, and mercifully, modify both verb phrases and sentences.”
Succinctness
Communication can be made more efficient or more clear
An editor recommending that lying be explicitly provisionally defined in a text that is about lying in a broad sense. Lying would be defined early on to include cases of lying by omission so as to avoid continually writing “lies (including lies by omission)”
Specificity
Communication of specific ideas can be made more efficient if words with diverse meanings are available
Advocating that sentience and consciousness be defined differently in general to have more specific words to use on a topic
Perception management
Incorrect use of words can make it seem like you’re not well-read or are trying to act more sophisticated than you are
An editor recommending that someone not use enormity to mean large size, as its dictionary definition is extreme wickedness and this could make readers think the author is naive (from The Sense of Style by Steven Pinker)
Bad ways to evaluate a definition
Bad reason
Why bad?
Example
Understood meaning from the past (i.e. the Etymological fallacy)
Meanings change over time
Arguing that short retain its past meaning. Because people in richer countries have gotten taller in the last couple hundred years, a short person meant something different then than it does now, even if the definition in the dictionary is the same
Fake consequences
Sometimes there are few consequences if a particular word is defined poorly
Arguing that music, if not defined, will degrade: “If we don’t have a definition of music that distinguishes it from other types of sound, it inevitably will lead to a degradation of the art.” from What is music? (4:31) by Become the Knight on Youtube
False claim to preservation of specificity
While new definitions can lead to confusion and lack of specificity, that’s not always the case
Arguing that restricting the word literally to mean “not figuratively” would help preserve that definition: “For sure, words change their meanings and acquire additional ones over time, but we can resist these if we think that doing so will help preserve a useful distinction. So it is with literally.” (Stan Carey 2011)
Others argue that its use as an intensifier doesn’t limit the use of its other definition because there’s never any confusion between which meaning is intended. “This is a common argument of the prescriptivist but they can rarely support the assertion with more than a couple of examples if any. So unless a prescriptivist can show at least 10 examples where this sort of ambiguity led to a real consequential misunderstanding in the last year, they deserve to be told to just shut up.” (Metaphor Hacker 2011)
Rejection of categorization, especially in arbitrary ways
While arbitrary categorization can be totally useless, other arbitrary categorizations are helpful, if not unavoidable
Rejecting genre classifications: “I entered three different songs in three different genre categories. My music doesn't fit neatly into a genre. Isn't it funny that a song can be R & B or folk or Americana, just based on how it's performed and produced?... Reader, I've grown weary of genres and labels, in all walks of my life. I miss getting to the core of humanity and art without trying to make everyone and everything fit neatly into a man-made box.” (Emily Hurd 2025)
Genres, like other messy categorizations, can help people search for things. Supermarkets categorize items in a way that helps customers search for them. Fingerprints were categorized arbitrarily in order to search for them before computers were able to do so (described in this video at 9:45)
Consistency with all common usage or intuitions
It’s impossible to create a definition that matches every intuition about what a word means
Expecting that many subdefinitions can fully describe a word's meaning. From Surfaces and Essences by Douglas Hofstadter and Emmanuel Sander:
“Take, for example, the noun “band”. In any reasonably-sized dictionary, there will be, in the overall entry for this word, a subentry describing a band as a piece of cloth that can be wrapped around things, another subentry describing how a band can be a colored strip or stripe on a piece of cloth or other type of surface... [S]ub-meanings are often closely related (for instance, the colored stripe and the range of frequencies, or the wedding ring and the piece of cloth wrapped around something), and because each of these supposedly clear and separate senses of the word “band” constitutes on its own a bottomless chasm of complexity.”
Sometimes conversations involve people using the same word differently. In the best case scenario, participants notice and choose a favorable provisional definition. Outside of conversations, people advocate for specific meanings to be adopted or not adopted more broadly. Below, I discuss reasonable and unreasonable ways people evaluate definitions, along with examples.
Good ways to evaluate a definition
Good reason
Why good?
Example
Practical applications
Some words’ and phrases’ definitions have practical applications
Scientists recommending that cancer 10–15 cm from the anal verge be defined as colon cancer rather than rectal cancer because it seems to respond to additional chemotherapy, which is also the case for colon cancer (Swets et al. 2017)
Scientists recommending that the definition of statistical significance be changed to p < 0.005 because it would help improve reproducibility (Benjamin et al. 2018)
Common usage
We use words to communicate with others; they have to understand us
An editor recommending that the term chips not be used to mean what Americans call French fries for an article with a global audience
A friend recommending that violence refer to acts causing physical damage for the duration of a conversation, since this is a common usage and is more intuitive than inclusion of mental damage
Standardization
It’s easier to communicate when there are commonly accepted definitions of words
Scientists recommending a more standardized definition of ecological terms like community in order to create more understanding (Stroud et al. 2015)
Factual correctness
Some words and phrases, especially scientific ones, are defined by the characteristics we’ve observed about them
Electricity changing in meaning from “The operations of a very subtil fluid, which appears to be diffused through most bodies, remarkable for the rapidity of its motion, and one of the most powerful agents in nature…” in 1828 (Webster) to “a fundamental form of energy observable in positive and negative forms that occurs naturally (as in lightning) or is produced (as in a generator) and that is expressed in terms of the movement and interaction of electrons” in 2026 (Merriam-Webster)
Carving nature at its joints
Words for categories are more useful if they reflect meaningful distinctions
Astronomers formally defining planet in 2006. One of the new criteria was whether an object has “cleared the neighborhood,” referring to whether it gravitationally dominates its orbital region. On measures of this property, the eight planets are separated from Pluto and other dwarf planets by a large gap. Although choosing where to draw a category boundary involves some arbitrariness, the definition tracks a substantial physical distinction among objects in the Solar System
Consistency with rules of the language
Languages can be made easier to learn
Recommending a similar use of hopefully to other adverbs. Historically, hopefully referred to doing something with hope, as in “Hopefully, he asked for a raise,” but now often expresses a desired outcome, as in “Hopefully, I get a raise.” This example is from The Sense of Style by Steven Pinker, where he notes that “many adverbs, such as candidly, frankly, and mercifully, modify both verb phrases and sentences.”
Succinctness
Communication can be made more efficient or more clear
An editor recommending that lying be explicitly provisionally defined in a text that is about lying in a broad sense. Lying would be defined early on to include cases of lying by omission so as to avoid continually writing “lies (including lies by omission)”
Specificity
Communication of specific ideas can be made more efficient if words with diverse meanings are available
Advocating that sentience and consciousness be defined differently in general to have more specific words to use on a topic
Perception management
Incorrect use of words can make it seem like you’re not well-read or are trying to act more sophisticated than you are
An editor recommending that someone not use enormity to mean large size, as its dictionary definition is extreme wickedness and this could make readers think the author is naive (from The Sense of Style by Steven Pinker)
Bad ways to evaluate a definition
Bad reason
Why bad?
Example
Understood meaning from the past (i.e. the Etymological fallacy)
Meanings change over time
Arguing that short retain its past meaning. Because people in richer countries have gotten taller in the last couple hundred years, a short person meant something different then than it does now, even if the definition in the dictionary is the same
Fake consequences
Sometimes there are few consequences if a particular word is defined poorly
Arguing that music, if not defined, will degrade: “If we don’t have a definition of music that distinguishes it from other types of sound, it inevitably will lead to a degradation of the art.” from What is music? (4:31) by Become the Knight on Youtube
False claim to preservation of specificity
While new definitions can lead to confusion and lack of specificity, that’s not always the case
Arguing that restricting the word literally to mean “not figuratively” would help preserve that definition: “For sure, words change their meanings and acquire additional ones over time, but we can resist these if we think that doing so will help preserve a useful distinction. So it is with literally.” (Stan Carey 2011)
Others argue that its use as an intensifier doesn’t limit the use of its other definition because there’s never any confusion between which meaning is intended. “This is a common argument of the prescriptivist but they can rarely support the assertion with more than a couple of examples if any. So unless a prescriptivist can show at least 10 examples where this sort of ambiguity led to a real consequential misunderstanding in the last year, they deserve to be told to just shut up.” (Metaphor Hacker 2011)
Rejection of categorization, especially in arbitrary ways
While arbitrary categorization can be totally useless, other arbitrary categorizations are helpful, if not unavoidable
Rejecting genre classifications: “I entered three different songs in three different genre categories. My music doesn't fit neatly into a genre. Isn't it funny that a song can be R & B or folk or Americana, just based on how it's performed and produced?... Reader, I've grown weary of genres and labels, in all walks of my life. I miss getting to the core of humanity and art without trying to make everyone and everything fit neatly into a man-made box.” (Emily Hurd 2025)
Genres, like other messy categorizations, can help people search for things. Supermarkets categorize items in a way that helps customers search for them. Fingerprints were categorized arbitrarily in order to search for them before computers were able to do so (described in this video at 9:45)
Consistency with all common usage or intuitions
It’s impossible to create a definition that matches every intuition about what a word means
Expecting that many subdefinitions can fully describe a word's meaning. From Surfaces and Essences by Douglas Hofstadter and Emmanuel Sander:
“Take, for example, the noun “band”. In any reasonably-sized dictionary, there will be, in the overall entry for this word, a subentry describing a band as a piece of cloth that can be wrapped around things, another subentry describing how a band can be a colored strip or stripe on a piece of cloth or other type of surface... [S]ub-meanings are often closely related (for instance, the colored stripe and the range of frequencies, or the wedding ring and the piece of cloth wrapped around something), and because each of these supposedly clear and separate senses of the word “band” constitutes on its own a bottomless chasm of complexity.”
This is a similar blog post to When is it worth it to argue over definitions? by Spencer Greenberg.