This is an interesting article that uses Google ngrams and the Corpus of Historical American English (COHA) to look at word trends.
Google ngrams charts the frequency of words in Google Books on a line graph. For instance, here is a chart of "grammar" and "rhetoric" between 1600 and 2012. I really which I could figure out how to embed the chart. I'll work on it.
COHA has more fields, more possibilities. It will do collocations, which is awesome (see the article). I need to play with it a bit more though to figure it out. (whoops!)
These might be really interesting in a class discussing connotation/denotation, and there are probably a lot of other possibilities. What do you think?
This post was also published on MUSE '13