Simply commercials about suits (7)
I believe the answer is:
adjusts
'suits' is the definition.
(I've seen this in another clue)
'simply commercials about' is the wordplay.
'simply' becomes 'just' (synonyms).
'commercials' becomes 'ads' (ad is short for advert).
'about' means one lot of letters goes inside another.
'just' inserted within 'ads' is 'ADJUSTS'.
(Other definitions for adjusts that I've seen before include "suits" , "Alters to regulate" .)