Another quick note on the LessWrong wiki:
I'm skeptical of single definitions without disclaimers. I think it's misleading (to some) that "Truth is the correspondence between and one's beliefs about reality and reality. ". Rather, it's fair to say that this is one specific definition of truth that has been used in many cases; I'm sure that others, including others on LessWrong, have used it differently.
Most dictionaries have multiple definitions for words. This seems more like what we should aim for.
In fairness, when I searched for "Rationality", the result states, "Rationality is something of fundamental importance to LessWrong that is defined in many ways", which I of course agree with.