Student loves convenience (3)
I believe the answer is:
loo
'convenience' is the definition.
(I know that convenience can be written as loo)
'student loves' is the wordplay.
'student' becomes 'l' (as in L-plates for learner drivers).
'loves' becomes 'oo' (love means 0 in tennis).
'l'+'oo'='LOO'
(Other definitions for loo that I've seen before include "A colloquial toilet" , "In which one goes" , "Little boys' room" , "Rest room" , "Card-game" .)