Helmsman's counterfeit coins: wax (8)
I believe the answer is:
coxswain
'helmsman's' is the definition.
(coxswain is a kind of helmsman)
'counterfeit coins wax' is the wordplay.
'counterfeit' is an anagram indicator.
'coins'+'wax'='coinswax'
'coinswax' is an anagram of 'COXSWAIN'.
(Other definitions for coxswain that I've seen before include "one over the eight" , "Person at the helm of a racing crew" , "one steers" , "Rowing boat pilot" , "Person steering a boat" .)