Old bit in gym and some games area (6)
I believe the answer is:
peseta
'old bit' is the definition.
(I've seen this before)
'gym and some games area' is the wordplay.
'gym' becomes 'pe'.
'and' is a charade indicator (letters next to each other).
'some games' becomes 'set' (I have seen 'games of tennis' mean 'set' so perhaps 'games' could also mean 'set').
'area' becomes 'a' (maths abbreviation).
'pe'+'set'+'a'='PESETA'
'in' is the link.
(Other definitions for peseta that I've seen before include "Old bit" , "Old money - see Pat (anag)" , "Spanish bread once" , "Former monetary unit of Spain" , "Former Spanish currency unit" .)