Conductor's chosen right verse (9)
I believe the answer is:
electrode
'conductor's' is the definition.
(electrode is a kind of conductor)
'chosen right verse' is the wordplay.
'chosen' becomes 'elect' ('elect' as an adjective can mean chosen).
'right' becomes 'r' (common abbreviation).
'verse' becomes 'ode'.
'elect'+'r'+'ode'='ELECTRODE'
(Other definitions for electrode that I've seen before include "Conductor (eg, in battery)" , "Conducting contact" , "Connecting conductor" , "Conductor making contact in a circuit" , "Terminal of, eg, an acid battery" .)