Note university students are boring (4)
I believe the answer is:
dull
'boring' is the definition.
(similar in meaning)
'note university students' is the wordplay.
'note' becomes 'd' (musical note).
'university' becomes 'U' (abbreviation for university).
'students' becomes 'LL' (an abbreviation for learner driver written twice).
'd'+'u'+'ll'='DULL'
'are' acts as a link.
(Other definitions for dull that I've seen before include "Lacking excitement" , "Lacking brightness" , "Lacklustre" , "Cloudy or boring" , "Lacking variety" .)