Complete with mouth (5)
I believe the answer is:
utter
This clue is a double definition.
'complete' is the first definition.
(I've seen this before)
'mouth' is the second definition.
('utter' can be a synonym of 'mouth')
'with' is the link.
(Other definitions for utter that I've seen before include "mouth" , "Speak; complete" , "Perfect" , "Say - complete" , "Absolutely" .)