Prohibit woman getting an instrument (5)
I believe the answer is:
banjo
'instrument' is the definition.
(banjo is a kind of instrument)
'prohibit woman getting' is the wordplay.
'prohibit' becomes 'ban' (banning is a kind of prohibiting).
'woman' becomes 'jo' ().
'getting' means one lot of letters go next to another.
'ban'+'jo'='BANJO'
'an' acts as a link.
(Other definitions for banjo that I've seen before include "Stringed instrument with long neck" , "Stringed instrument with circular body" , "Uke's relative" , "String instrument" , "Instrument with long neck and round body" .)