Consequences of a fine period of work at Harrow, primarily (9)
I believe the answer is:
aftermath
'consequences' is the definition.
(the aftermath of something is its consequences)
'a fine period of work at harrow primarily' is the wordplay.
'fine' becomes 'f' (abbreviation).
'period of work' becomes 'term' (eg term in a particular post).
'primarily' says to take the initial letters.
The first letter of 'harrow' is 'h'.
'a'+'f'+'term'+'at'+'h'='AFTERMATH'
'of' is the link.
(Other definitions for aftermath that I've seen before include "Subsequent circumstances" , "Circumstances that follow an event" , "Frame that in following events" , "Repercussions" , "Results, often of something bad" .)