Sound for attention (4)
I believe the answer is:
ahem
'sound for attention' 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 "Polite word to draw attention" , "Throat-clearing noise?" , "Polite noise to draw attention" , "call attracting attention" , "that's said to attract attention" .)