Insignificant worker in company? Good (3)
I believe the answer is:
cog
'insignificant worker' is the definition.
(a cog in a machine)
'company? good' is the wordplay.
'company?' becomes 'co' (abbreviation).
'good' becomes 'g' (abbreviation).
'co'+'g'='COG'
'in' acts as a link.
(Other definitions for cog that I've seen before include "bar" , "Wheel with projections" , "Minor person in organisation" , "One has teeth" , "Projection on a toothed wheel" .)