Stray cat? If so, stray's OK! (12)
I believe the answer is:
satisfactory
'ok' is the definition.
(I've seen this before)
'stray cat? if so stray's' is the wordplay.
'stray's' is an anagram indicator (I've seen 'stray' mean this).
'stray'+'cat'+'if'+'so'='straycatifso'
'straycatifso' is an anagram of 'SATISFACTORY'.
(Other definitions for satisfactory that I've seen before include "Fully acceptable" , "fine" , "Acceptable - adequate" , "unexceptional" , "Good enough" .)