Idle chatter has teeth on edge (7)
I believe the answer is:
ratchet
'teeth on edge' is the definition.
'ratchet' can be an answer for 'teeth' (I've seen this before). I'm unsure of the 'on edge' bit.
'idle chatter' is the wordplay.
'chatter' can be anagrammed to 'RATCHET'.
However, I'm unsure how this is indicated.
'has' is the link.
Can you help me to learn more?
(Other definitions for ratchet that I've seen before include "Device promoting One Direction" , "Device allowing motion in one direction only" , "Bar that fits into the notches of a toothed wheel" , "It forces one-way motion" , "Device consisting a toothed wheel and pawl that allows movement in one direction only" .)