Words worth looking up because oh man do they change meaning include: nice, buxom, and lewd.

My first exposure to this with any rigor was in high school. We were given one of shakespeare’s sonnets to analyze and the first thing we had to to was go to the library and look up literally every word in the sonnet in the OED and consider only those senses of the word that dated to date of composition or prior. A LOT of words didn’t mean to shakespeare what you think they mean now!