Thanks to students being huge (4)
I believe the answer is:
tall
'being huge' is the definition.
(thesaurus)
'thanks to students' is the wordplay.
'thanks' becomes 'ta' (UK informal version of 'thank you').
'to students' becomes 'll' (two abbreviations for learner).
'ta'+'ll'='TALL'
(Other definitions for tall that I've seen before include "High in stature" , "Lofty; unlikely" , "Of great height" , "Higher than the average person" , "that's hard to swallow" .)