Brave face social worker put on (7)
I believe the answer is:
gallant
'brave' is the definition.
(similar in meaning)
'face social worker put on' is the wordplay.
'face' becomes 'gall' (face can mean gall or insolence).
'social worker' becomes 'ant' (I've seen this in another clue).
'put on' says to put letters next to each other.
'gall'+'ant'='GALLANT'
(Other definitions for gallant that I've seen before include "Courageous - politely attentive to women" , "lady-killer?" , "Valiant; courteous" , "Chivalrous - dashing" , "Noble, chivalrous" .)