Independent test after end of term must be better (7)
I believe the answer is:
improve
'better' is the definition.
(I know that better can be written as improve)
'independent test after end of term' is the wordplay.
'independent' becomes 'i'.
'test' becomes 'prove' (synonyms).
'after' is a charade indicator (letters next to each other).
'end of' indicates one should take the final letters.
The last letter of 'term' is 'm'.
'prove' after 'm' is 'mprove'.
'i'+'mprove'='IMPROVE'
'must be' acts as a link.
(Other definitions for improve that I've seen before include "pick up" , "Polish" , "Make better in quality" , "Make progress" , "reform" .)