Game to give the wife the key to get in (6)
I believe the answer is:
bridge
'game' is the definition.
(card game)
'the wife the key to get in' is the wordplay.
'the wife' becomes 'bride' (I have seen 'Wife of groom ' mean 'bride' so perhaps 'wife' could also mean 'bride').
'the key' becomes 'g' (musical key).
'to get in' indicates putting letters inside.
'bride' placed around 'g' is 'BRIDGE'.
'to give' is the link.
(Other definitions for bridge that I've seen before include "Connection crossing river etc" , "Partial denture; span" , "Requirement for spectacles" , "Span or connect" , "British composer" .)