Give worst cry of pain (6)
I believe the answer is:
bestow
'give' is the definition.
(bestowing is a kind of giving)
'worst cry of pain' is the wordplay.
'worst' becomes 'best' (both can mean to beat someone).
'cry of pain' becomes 'ow' (I've seen this in other clues).
'best'+'ow'='BESTOW'
(Other definitions for bestow that I've seen before include "Confer (an honour)" , "Confer or award" , "Set bow to give" , "Present, donate" , "Grant" .)