Undergraduate ultimately failing to pass (6)
I believe the answer is:
elapse
'to pass' is the definition.
(synonyms)
'undergraduate ultimately failing' is the wordplay.
'ultimately' says to take the final letters.
'failing' becomes 'lapse' (I've seen this before).
The last letter of 'undergraduate' is 'e'.
'e'+'lapse'='ELAPSE'
(Other definitions for elapse that I've seen before include "Passing" , "Go by - pass away" , "Pass away - asleep (anag)" , "Slip away" , "Go past" .)