One working with Norma on hill? (8)
I believe the answer is:
operator
'one working' is the definition.
'norma on hill?' is the wordplay.
'norma' becomes 'opera' (norma is an opera by vincenzo bellini).
'on' is a charade indicator (letters next to each other).
'hill?' becomes 'tor' (tor is a kind of hill).
'opera'+'tor'='OPERATOR'
'with' is the link.
(Other definitions for operator that I've seen before include "Switchboard employee" , "Poor rate for a businessman" , "Agent that runs some apparatus or machine" , "Speculator" , "Machinist -- or surgeon?" .)