An odd finding

I just finished Shakespeare's "The Taming of the Shrew" tonight. Shakespeare uses the word "wench" a lot in reference to women, even in a good sense, so I decided to make sure I was interpreting the word correctly. Here is what I found (Oxford Dictionary):

wench |wen ch |noun archaic or humorousa girl or young woman.• archaic a prostitute.

To my surprise the definition that I always thought of was the archaic one. For some reason society has made this word take on its older meaning rather than its more prominent (I say "prominent" describing the first, real definition above) and correct (?) definition.

Needless to say I will not be using this word in my everyday vocabulary, but it is interesting to see how we choose definitions; mainly the more detrimental ones (example: "ass").