Notice disc trouble (3)
I believe the answer is:
ado
'trouble' is the definition.
(both can mean bother or commotion)
'notice disc' is the wordplay.
'notice' becomes 'ad' (short for advert).
'disc' becomes 'O' (disc-shaped letter).
'ad'+'o'='ADO'
(Other definitions for ado that I've seen before include "Fuss or bustle" , "puff ball!" , "Fuss, difficulty" , "stew is provided" , "hoo-hah" .)