A coin’s silly in a gambling place (6)
I believe the answer is:
casino
'a gambling place' is the definition.
(I've seen this before)
'a coin's silly in' is the wordplay.
'silly' is an anagram indicator.
'in' is an insertion indicator.
'coins' anagrammed gives 'csino'.
'a' inserted within 'csino' is 'CASINO'.
(Other definitions for casino that I've seen before include "Where our betters show" , "Gambling venue" , "Gaming place" , "Place for better" , "enterprise?" .)