Finishes the school session in different seat (10)
I believe the answer is:
terminates
'finishes' is the definition.
(I know this)
'school session in different seat' is the wordplay.
'school session' becomes 'term' (I've seen this in another clue).
'different' is an anagram indicator.
'seat' is an anagram of 'ates'.
'term'+'in'+'ates'='TERMINATES'
'the' is the link.
(Other definitions for terminates that I've seen before include "Finishes" , "Ends" , "Stops" .)