I mentioned elsewhen that I have a whole bunch of dictionaries I refer to when researching words. just as a for instance, from Eugene Ehrlich's The Highly Selective Dictionary for the Extraordinarily Literate comes this:

Do not confuse quash with squash. Uprisings and indictments are quashed; hats and ripe grapes are squashed. But see squelch, which in one of its meanings is synonymous with quash.

this book is a wonderful resource for the not to be confused with theme.