Individual touring clubs in days gone by (4)
I believe the answer is:
once
'in days gone by' is the definition.
(I've seen this before)
'individual touring clubs' is the wordplay.
'individual' becomes 'one' (an individual is one person).
'touring' indicates putting letters inside (tour can mean to go around).
'clubs' becomes 'c' (abbreviation in card games).
'one' going around 'c' is 'ONCE'.
(Other definitions for once that I've seen before include "In former times" , "Formerly; as soon as" , "In days gone by" , "One-time - one time" , "in bygone era" .)