Homer's utterance (3)
I believe the answer is:
doh
'homer's utterance' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for doh that I've seen before include "for 7 [HOMER] of course!" , "annoyed expression" , "First note of musical scale" , "an exclamation from someone who's annoyed with himself" , "First note of major scale in music" .)