Throat-clearing utterance (4)
I believe the answer is:
ahem
'throat-clearing utterance' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for ahem that I've seen before include "Sound made when clearing throat" , "Exclamation attracting attention" , "call attracting attention" , "Cough to draw attention" , "Expression of disapproval" .)