Couple in act outside university (3)
I believe the answer is:
duo
'couple' is the definition.
('duo' can be a synonym of 'couple')
'act outside university' is the wordplay.
'act' becomes 'do' (I've seen this in other clues**).
'outside' indicates putting letters inside.
'university' becomes 'u'.
'do' going around 'u' is 'DUO'.
'in' is the link.
(Other definitions for duo that I've seen before include "A team of two" , "Couple, pair" , "Two-person act" , "rejected Arab's lute" , "entertainers such as Eric and Ernie" .)