It means little at the end of term, note (5)
I believe the answer is:
minim
'note' is the definition.
(musical note)
'it means little at the end of term' is the wordplay.
'it means little' becomes 'mini' (I can't explain this - if you can you should believe this answer much more).
'at the end of' says to take the final letters.
The final letter of 'term' is 'm'.
'mini'+'m'='MINIM'
Can you help me to learn more?
(Other definitions for minim that I've seen before include "Feature of a score" , "Palindromic note" , "Quarter of a breve" , "Musical note - small amount of liquid" , "note or > dose" .)