On the first of December, we got married (3)
I believe the answer is:
wed
'married' is the definition.
(wed can mean married)
'on the first of december we' is the wordplay.
'on' is a charade indicator (letters next to each other).
'the first of december' becomes 'd' (1st letter of 'december').
'd' put after 'we' is 'WED'.
'got' acts as a link.
(Other definitions for wed that I've seen before include "Join" , "united" , "Married" , "Unite closely" , "Joined in the dew" .)