School crayons Ed chewed (9)
I believe the answer is:
secondary
'school' is the definition.
(secondary school is a kind of school)
'crayons ed chewed' is the wordplay.
'chewed' indicates anagramming the letters.
'crayons'+'ed'='crayonsed'
'crayonsed' anagrammed gives 'SECONDARY'.
(Other definitions for secondary that I've seen before include "One grade below the first" , "Of lesser importance" , "Derivative - of minor importance" , "Of lesser important" , "Subsidiary" .)