[furyofantares]

> However, to be an honest descriptivist, you must acknowledge that words are used in certain ways more frequently than others. Definitions attempt to capture the canonical usage of a word.

True. And that's generally how they order the definitions in the dictionary, in order of usage.

For example, "an unfounded or mistaken impression or notion" is indeed the 2nd definition in M-W for "hallucination", not the first.

[trehalose]

A dictionary entry's second definition isn't necessarily an uncommonly used one. It could be up to 49% of the word's usage (assuming the dictionary has such precise statistics).