A half-assed wedding. Whereas "wedding = proper ceremony + proper reception", a weddin will not have one or both of these. Also called "a family reunion".
Weddins are often trying to seem like chic, cost-effective weddings, but end up looking like the couple are cheap as hell and don't really give a shit about their wedding or their guests.
Examples:
Saying vows and signing the marriage license without an officiant
Getting a food truck instead of catering
Having your guests play frisbee and board games instead of dancing
Having your ceremony and reception in a Walmart parking lot
"Are you going to his weddin? I hear that he got a food truck, borrowed an old boom box and 3 CDs, and that the bride is wearing cutoffs."