Old saw that's lost its cutting edge (6)

I believe the answer is:

cliche

I'm a little stuck... Click here to teach me more about this clue!

'old saw' is the definition.
(I've seen this in another clue)

I cannot understand how the rest of the clue works.

(Other definitions for cliche that I've seen before include "Hackneyed expression" , "Tired 21/12 [TURN OF PHRASE]" , "Saying repeated too often" , "Trite phrase" , "Hackneyed phrase, boring through repetition" .)

I've seen this clue in The Globe and Mail.

Want a hint initially instead of a full solution? Install my app