Words are wise men’s counters, they do but reckon by them; but they are the money of fools, that value them by the authority of an Aristotle, a Cicero, or a Thomas, or any other doctor whatsoever, if but a man.
Thomas Hobbes – Leviathan
Eliezer Yudkowsky is regarded something of an authority on rationality, and he’s written quite a lot about this.
37 Ways That Words Can Be Wrong is an interesting cluster of ideas about words, what they mean, and what we try to make them do that we really shouldn’t.
Disputing Definitions and The Argument From Common Usage are good places to start.