I remember some stuff from Historical Linguistics, but my book is not in my room right now - it's in the lab, because I brought all my books there at the end of the semester so I wouldn't have to move them. I'll get an answer to you tomorrow when I can get my book, but I do remember when we were talking about historical semantics changes and they did talk about something with words sounding like other words and then falling into disuse for that reason.

-Alex