[I'm right here, you know] (4)
I believe the answer is:
ahem
'i'm right here you know' 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 used to attract attention" , "Cough to draw attention" , "Attention-grabbing expression" , "It's said to gain attention; ah, me (anag.)" , "Excuse me!" .)