[repsilat]

Some argue that "cliche" is onomatopoeic.

http://en.wikipedia.org/wiki/Cliche#Origin

A world like onomatopoeia being onomatopoeic isn't that far-fetched. Perhaps the word could be named after a very common onomatopoeia, perhaps one that has gone out of use. A word with that sort of etymology is "shibboleth" - its current meaning is derived from what was a common shibboleth.