Small thanks to students on kiosk (5)
I believe the answer is:
stall
'kiosk' is the definition.
(I know that kiosk can be written as stall)
'small thanks to students on' is the wordplay.
'small' becomes 's' (abbreviation - e.g. clothes size).
'thanks' becomes 'ta' (UK informal version of 'thank you').
'to students' becomes 'll' (two abbreviations for learner).
'on' is a charade indicator (letters next to each other).
's'+'ta'+'ll'='STALL'
(Other definitions for stall that I've seen before include "Enclosure" , "Delay - booth for selling goods" , "Booth; prevaricate" , "Hold up" , "Stable compartment" .)