In french la cérémonie de mariage, bryllup, exists : "les épousailles" or "Les noces" It is perfectly correct but not as commonly used.
Union could be used too but it is very formal and administrative. "Nous sommes ici pour célébrer l'union de Paul et Virginie". There is a word in danish for this verb : Vie, meaning unir, (By the holy bonds of marriage) or épouser (Une cause). Very solemn or a joke, depends who speaks.
Note there is a completely different danish word "gifte sig" for the verb to marry (usually with someone). "Kan jeg gifte mig igen?"
I like the word épousailles but it is very difficult to pronunce.
et bryllup is a wedding, for anyone looking for the Danish term.
For confirmation see also:
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Hvornår er jeres bryllup? https://www.duolingo.com/comment/17764631
ægteskaberne (which has discussions of the differences, which support allintolearning's description here) https://www.duolingo.com/comment/6052760