Attention-seeking utterance (4)
I believe the answer is:
ahem
'attention-seeking utterance' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for ahem that I've seen before include "Sound made when clearing throat" , "Excuse me!" , "Utterance of mild disapproval" , "attempt to attract attention" , "Noise made when clearing throat (4" .)