Were a couple of hours fairly employed in school? (9)
I believe the answer is:
cohabited
'were a couple' is the definition.
(people cohabiting are living together as a couple)
'hours fairly employed in school?' is the wordplay.
'hours' becomes 'h'.
'fairly' becomes 'a bit' (both can mean somewhat or to some extent).
'employed in' means one lot of letters goes inside another.
'school?' becomes 'coed' (a co-educational school).
'h'+'abit'='habit'
'habit' placed inside 'coed' is 'COHABITED'.
'of' acts as a link.
(Other definitions for cohabited that I've seen before include "Lived together" , "came together under one roof" .)