Finding record old? Extremely (9)
I believe the answer is:
discovery
'finding' is the definition.
(thesaurus)
'record old? extremely' is the wordplay.
'record' becomes 'disc' ('disc' can be a synonym of 'record').
'old?' becomes 'o' (common abbreviation eg in OE for Old English).
'extremely' becomes 'very' (I've seen this before).
'disc'+'o'+'very'='DISCOVERY'
(Other definitions for discovery that I've seen before include "Something newly found" , "Process of finding" , "Find - Scott's ship" , "Thing found (or the finding)" , "old ship" .)