Publicity leads to huge troubles (4)
I believe the answer is:
ados
'troubles' is the definition.
(I've seen this before)
'publicity leads to huge' is the wordplay.
'publicity' becomes 'ad' (advert).
'leads' means one lot of letters go next to another.
'to huge' becomes 'os' (abbreviation for outsize).
'ad'+'os'='ADOS'
(Other definitions for ados that I've seen before include "fuss, trouble, difficulty and the rest" , "Troubles" , "Stirs" , "Bothers" , "Fusses" .)