Is no longer with a society (3)
I believe the answer is:
was
'is no longer' is the definition.
(I've seen this before)
'with a society' is the wordplay.
'with' becomes 'w' (abbreviation).
'society' becomes 's' (common abbreviation in names of organisations).
'w'+'a'+'s'='WAS'
(Other definitions for was that I've seen before include "'Is, in the past (3)'" , "(He/she/it) existed" , "Did live" , "Is no longer" , "Existed in the past" .)