Swot showing face at university (3,2)
I believe the answer is:
mug up
'swot' is the definition.
('mug up' can be a synonym of 'swot')
'face at university' is the wordplay.
'face' becomes 'mug' (mug is a kind of face**).
'at university' becomes 'up'.
'mug'+'up'='MUG UP'
'showing' acts as a link.
(Other definitions for mug up that I've seen before include "Cram" , "Quickly revise" , "Learn (subject) quickly" , "Make an intensive study" , "Learn subject rapidly" .)