Short measure of alcohol immediately after wedding (5)
I believe the answer is:
union
'wedding' is the definition.
(I've seen this in another clue)
I can't explain the rest of the clue.
Can you help me to learn more?
(Other definitions for union that I've seen before include "A joining together as in marriage" , "workers' co-operative" , "Association - guild" , "Workers' group" , "Coalition" .)