Is fairly discontented after school test answer (7)
I believe the answer is:
satisfy
'answer' is the definition.
(thesaurus)
'is fairly discontented after school test' is the wordplay.
'discontented' means to remove the middle letters.
'after' says to put letters next to each other.
'school test' becomes 'SAT' (abbreviation for standard attainment test).
'fairly' with its middle removed is 'fy'.
'is'+'fy'='isfy'
'isfy' after 'sat' is 'SATISFY'.
(Other definitions for satisfy that I've seen before include "To convince" , "Fulfill requirements" , "indulge" , "Content" , "Make contented, fill need" .)