Formerly outside university when expected (2,3)
I believe the answer is:
on cue
'when expected' is the definition.
(I've seen this before)
'formerly outside university' is the wordplay.
'formerly' becomes 'once' (synonyms).
'outside' indicates putting letters inside (some letters go outside others).
'university' becomes 'U' (abbreviation for university).
'once' placed around 'u' is 'ON CUE'.
(Other definitions for on cue that I've seen before include "at the perfect moment" , "(Appearing) just when required" , "Pat" , "When signalled" , "Where chalk may be put" .)