Social occasion around Oxford University gets to become regular (4,3)
I believe the answer is:
even out
'to become regular' is the definition.
(become even or regular)
'social occasion around oxford university' is the wordplay.
'social occasion' becomes 'event' (I've seen this in another clue).
'around' is an insertion indicator.
'oxford university' becomes 'OU'.
'event' placed around 'ou' is 'EVEN OUT'.
'gets' acts as a link.
(Other definitions for even out that I've seen before include "Make level" , "reach consistent level" , "Make flat" , "Become equal" , "Smooth" .)