Stray owls seen heading for recreation ground (9)
I believe the answer is:
ownerless
'stray' is the definition.
'owls seen heading for recreation ground' is the wordplay.
'heading for' indicates taking the first letters.
'ground' is an anagram indicator (solvers must 'grind' the letters into a new form).
The initial letter of 'recreation' is 'r'.
'owls'+'seen'+'r'='owlsseenr'
'owlsseenr' is an anagram of 'OWNERLESS'.
(Other definitions for ownerless that I've seen before include "Not possessed by anyone" , "common, perhaps" .)