Time with old couple (3)
I believe the answer is:
two
'couple' is the definition.
(a couple can mean two of something)
'time with old' is the wordplay.
'time' becomes 't' (abbreviation).
'with' becomes 'w' (abbreviation).
'old' becomes 'o' (common abbreviation eg in OE for Old English).
't'+'w'+'o'='TWO'
(Other definitions for two that I've seen before include "''... turtle doves''" , "2" , "'It takes ? to tango'" , "Cat's coat" , "Number of Gentlemen of Verona" .)