Possibly Jacob’s novel record (5)
I believe the answer is:
sheep
'possibly jacob's' is the definition.
(Jacob sheep is a breed of sheep)
'novel record' is the wordplay.
'novel' becomes 'she' (I've seen this before).
'record' becomes 'EP' (abbreviation for extended play record).
'she'+'ep'='SHEEP'
(Other definitions for sheep that I've seen before include "Source of lamb" , "Gregarious animal(s)" , "Wool provider" , "Dolly or Shaun" , "- may safely graze (Bach)" .)