It delays trader, getting involved with worker, perhaps (9)
I believe the answer is:
retardant
'it delays' is the definition.
(I've seen this before)
'trader getting involved with worker perhaps' is the wordplay.
'getting involved' is an anagram indicator.
'with' is a charade indicator (letters next to each other).
'worker perhaps' becomes 'ant' (worker is a type of ant).
'trader' is an anagram of 'retard'.
'retard'+'ant'='RETARDANT'
(Other definitions for retardant that I've seen before include "Preventing, inhibiting" , "It delays" , "Inhibiting substance" , "having slowing effect" , "Substance suppressing fire" .)