Some carping at education kept in school (5)
I believe the answer is:
gated
'kept in school' is the definition.
(I've seen this before)
'some carping at education' is the wordplay.
'some' says the answer is hidden in the clue (some of the parts of the word are used).
'GATED' is hidden in the letters of 'carping at education'.
(Other definitions for gated that I've seen before include "Under curfew" , "temporarily confined" , "Forbidden to leave college" , "kept in school" , "Confined to school" .)