Prepared for study with head of year (5)
I believe the answer is:
ready
'prepared' is the definition.
(associated in meaning)
'study with head of year' is the wordplay.
'study' becomes 'read' (synonyms).
'with head of' says to take the initial letters.
The first letter of 'year' is 'y'.
'read'+'y'='READY'
'for' is the link.
(Other definitions for ready that I've seen before include "Cash; within reach" , "game?" , "Poised for action" , "All set to go" , "In addition" .)