Ham provided by girl in October (7)
I believe the answer is:
overact
'ham' is the definition.
(ham can mean to overact)
'girl in october' is the wordplay.
'girl' becomes 'vera' ().
'in' is an insertion indicator.
'october' becomes 'Oct' (synonyms).
'vera' put into 'oct' is 'OVERACT'.
'provided by' acts as a link.
(Other definitions for overact that I've seen before include "Play part exaggeratedly" , "In part, fail to convince" , "Be excessive like fulsome thespian" , "Be excessive on stage" , "Perform with exaggeration" .)