Comply when told to go (6)
I believe the answer is:
assent
'comply' is the definition.
('assent' can be a synonym of 'comply')
'when told to go' is the wordplay.
'when' becomes 'as'.
'told to go' becomes 'sent'.
'as'+'sent'='ASSENT'
(Other definitions for assent that I've seen before include "Accede, agree" , "Give consent" , "Official sanction" , "Agree, acquiesce" , "Nod" .)