Gave vent to anger in commercial (5)
I believe the answer is:
aired
'gave vent' is the definition.
(air can mean to vent or express)
'anger in commercial' is the wordplay.
'anger' becomes 'ire' (synonyms).
'in' is an insertion indicator.
'commercial' becomes 'ad' (abbreviation for advertisement).
'ire' inserted into 'ad' is 'AIRED'.
'to' acts as a link.
(Other definitions for aired that I've seen before include "Broadcast; dried" , "Exposed for drying" , "Raised" , "Ventilated in the outdoors?" , "Put to dry; said publicly" .)