Language held by girl in gold (5)
I believe the answer is:
lingo
'language' is the definition.
(informal term for language)
'held by girl in gold' is the wordplay.
'held by' indicates the answer is hidden within the clue.
'LINGO' is hidden in the letters of 'girl in gold'.
(Other definitions for lingo that I've seen before include "Tongue" , "Patois" , "Parlance" , "Jargon, foreign language (informal)" , "Log in (anag.)" .)