Record many an own goal (3)
I believe the answer is:
log
'record' is the definition.
(log is a kind of record)
'many an own goal' is the wordplay.
'many' becomes 'l' ().
'an own goal' becomes 'OG' (football abbreviation).
'l'+'og'='LOG'
(Other definitions for log that I've seen before include "Formal record" , "Piece of wood - record" , "Record book; tree part" , "Official record; cut part of tree trunk" , "Official record of events" .)