Links university with atheism, regularly (6)
I believe the answer is:
unites
'links' is the definition.
('unite' can be a synonym of 'link')
'university with atheism regularly' is the wordplay.
'university' becomes 'uni' (short for university).
'with' says to put letters next to each other.
'regularly' means one should take alternating letters (regularly take one letter, leave next etc.).
The alternating letters of 'atheism' are 'tes'.
'uni'+'tes'='UNITES'
(Other definitions for unites that I've seen before include "Joins together as one" , "Confederates" , "Joins or brings together" , "Comes together as one" , "Becomes one" .)