Getting on coach for Greyfriars, say (8,6)
I believe the answer is:
boarding school
'greyfriars say' is the definition.
(Greyfriars is a fictional boarding school)
'getting on coach' is the wordplay.
'getting on' becomes 'boarding' ('board' can be a synonym of 'get on').
'coach' becomes 'school' (both can mean to teach or train).
'boarding'+'school'='BOARDING SCHOOL'
'for' is the link.
(Other definitions for boarding school that I've seen before include "Winchester, maybe" , "Greyfriars, maybe" , "Eton, say" , "Roedean, say" , "Winchester, perhaps" .)