Approve pieces on time, okay? (11)
I believe the answer is:
endorsement
'okay?' is the definition.
(okay is a kind of endorsement)
'approve pieces on time' is the wordplay.
'approve' becomes 'endorse' (endorse can mean to approve or support).
'pieces' becomes 'men' (e.g. in chess).
'on' says to put letters next to each other (in a down clue, letters appear on others).
'time' becomes 't' (abbreviation).
'endorse'+'men'+'t'='ENDORSEMENT'
(Other definitions for endorsement that I've seen before include "Want backing" , "unwelcome to offending motorists" , "Official sanction or approval" , "Note on a driving licence" , "Penalty appended to driving licence" .)