Place to exchange vows (5)
I believe the answer is:
altar
'place to exchange vows' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for altar that I've seen before include "Where we will vow" , "A ceremonial table for worshipping" , "Consecrated table in church" , "Church focus for ritual" , "section of church" .)