Word for time spent at school (4)
I believe the answer is:
term
I believe this is a double definition.
'word' is the first definition.
(term is a kind of word)
'time spent at school' is the second definition.
(I've seen this before)
'for' is the link.
(Other definitions for term that I've seen before include "School time; word" , "Period of school life" , "Part of the school year" , "Hilary, in a > word" , "A fixed or limited time - or an expression" .)