Cancelled new university students (4)
I believe the answer is:
null
'cancelled' is the definition.
Both the definition and answer are adjectives. Perhaps they are linked in a way I don't understand?
'new university students' is the wordplay.
'new' becomes 'n' (common abbreviation eg NT for New Testament).
'university' becomes 'U' (abbreviation for university).
'students' becomes 'LL' (two abbreviations for learner).
'n'+'u'+'ll'='NULL'
Can you help me to learn more?
(Other definitions for null that I've seen before include "Without force, validity" , "Invalid - not binding" , "Having the value zero -- void" , "... and void, lacking any legal or binding force" , "Lacking any legally binding force" .)