"May I interrupt?” (4)
I believe the answer is:
ahem
'may i interrupt?' 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 "Noise used to attract attention" , "Excuse me!" , "request for attention" , "Polite noise to draw attention" , "Polite word to draw attention" .)