WordNet
n. the anniversary of the day on which you were married (or the celebration of it)
Wikipedia
A wedding anniversary is the anniversary of the date a marriage took place. Traditional names exist for all of them: for instance, 50 years of marriage is called a "golden wedding anniversary" or simply a "golden anniversary". Twenty-five years is called a "silver wedding anniversary" or "silver anniversary". Sixty years is a "diamond wedding anniversary" or "diamond anniversary". First year anniversary is called a "Paper Anniversary".
Usage examples of "wedding anniversary".
He managed to miss her all that afternoon, and he realized as he walked around that it was his wedding anniversary that day.
Daphne didnt add that it was the same kind her mother had planned on serving at the party for her fortieth wedding anniversary.
They'd all four first eaten at the restaurant in February 1973, for Mum and Dad's twentieth wedding anniversary.