Start working with clique (5)
I believe the answer is:
onset
'start' is the definition.
(both can mean the beginning of something)
'working with clique' is the wordplay.
'working' becomes 'on' (on can mean working or activated).
'with' is a charade indicator (letters next to each other).
'clique' becomes 'set' (a clique is a social set).
'on'+'set'='ONSET'
(Other definitions for onset that I've seen before include "First signs" , "origin" , "Beginning (of something often unpleasant)" , "Attack using stone" , "Beginning or early stages" .)