Day to get married (3)
I believe the answer is:
wed
I believe this clue is a double definition.
'day' is the first definition.
(abbreviation for Wednesday)
'get married' is the second definition.
('wed' can be a synonym of 'get married')
'to' acts as a link.
(Other definitions for wed that I've seen before include "united" , "Married" , "Join" , "Unite closely" , "Joined in the dew" .)