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The eutectic and eutectoid points are quite similar ideas: both are about a homogeneous material that changes into a mixture of two solid phases as it cools.  However, eutectic goes from a liquid to a pair of solid phases (liquid iron into the austenite and cementite phases in the example above), while eutectoid goes from one solid phase to two (austenite into ferrite and cementite).


If you wanted to use the same word for both points, then you'd need some other way of disambiguating them.  Maybe the "austenite easy transition point" and "liquid easy transition point"?

I don't think that giving similar-meaning words similar labels is a good idea.  In one class, I had to struggle to distinguish between:

  • hypoeutectoid ("less than well-melting-ish", such as steel with 0.022%-0.76% carbon)
  • hypereutectoid ("more than well-melting-ish", such as steel with 0.76%-2.14% carbon)
  • hypoeutectic ("less than well-melting", such as cast iron with 2.14%-4.30% carbon)
  • hypereutectic ("more than well-melting", such as cast iron with >4.30% carbon)

(see https://en.wikipedia.org/wiki/Eutectic_system#Eutectoid for more details)

Although hypo- and hyper- don't conform to your system (they have opposite meanings but similar sounds), -oid and -ic do, and it causes confusion and misunderstanding.

Re: dehumidifiers

A standalone dehumidifier will heat the air more than sweating can cool it.  You can see that from conservation of energy and thermodynamics: evaporating water (eg. when you sweat) absorbs heat , and condensing water (eg. in a dehumidifier) releases an equal amount.  You also need to pay a bit of extra energy to run the machine and to overcome entropy.

Using an air conditioner to dehumidify doesn't have that same problem, as it vents the heat outside.