Sociable society expenditure (9)
I believe the answer is:
outgoings
'expenditure' is the definition.
(I've seen this before)
'sociable society' is the wordplay.
'sociable' becomes 'outgoing' ('outgoing' can be similar in meaning to 'sociable').
'society' becomes 's' (common abbreviation in names of organisations).
'outgoing'+'s'='OUTGOINGS'
(Other definitions for outgoings that I've seen before include "Expenses" , "Regular expenditure" , "expeditions" .)