So, from your example, wwh, it appears that stereotype and cliché were full-fledged metaphors, but have transpired into something else: a metaphor taken from a previous period of time that has lost the metaphorical connection and stands more on its current definition than on the previous metaphorical connection.

I agree with Faldage that this is something that goes beyond metaphor. It is something that typically happens in language all the time--a word derives its meaning from a metaphorical connection, but, after being in use for a long period, that connection could become generally unknown or forgotten.

It's sweet to rediscover those metaphorical connections--like the one Faldage mentioned this morning that onions had previously meant "large pearls," which is definitely metaphorical. We can look at onions now with new appreciation--it returns us to the poetry implicit in language, don't you think?