Sanctimonious chap probing both sides of emotive affair (7)
I believe the answer is:
episode
'affair' is the definition.
(thesaurus)
'sanctimonious chap probing both sides of emotive' is the wordplay.
'sanctimonious' becomes 'pi' (old-fashioned term for pious).
'chap' becomes 'sod' (sod can rudely mean a person).
'probing' means one lot of letters goes inside another (probe can mean to poke or prod into).
'both sides of' suggests removing the centre (only the letters on the sides remain).
'emotive' with its middle taken out is 'ee'.
'pi'+'sod'='pisod'
'pisod' inserted within 'ee' is 'EPISODE'.
(Other definitions for episode that I've seen before include "Event or series of events in a story" , "Distinctive incident" , "Instalment; event" , "Part of TV series" , "One programme of a series" .)