Become indignant when wedding is announced (6)
I believe the answer is:
bridle
'become indignant' is the definition.
(I've seen this before)
'wedding is announced' is the wordplay.
'wedding' becomes 'bridal' (bridal is a kind of wedding).
'is announced' indicates a 'sounds like' (homophone) clue.
'bridal' is a homophone of 'BRIDLE'.
'when' is the link.
(Other definitions for bridle that I've seen before include "Headgear used to control a horse" , "Check" , "Horse restraint" , "Restrain" , "Bristle" .)