This word is commonly seen in the wedding invitations most especially in the Asian region. Let's make some clarification...
NUPTIAL - from www.dictionary.com
1. of or marriage or the marriage ceremony: the nuptial vows.
2. of, pertaining to, of mating the season of animals: nuptial behavior.
3. Usually, nuptials. a wedding or marriage.
The word “Nuptial”… is an adjective which refers to the marriage ceremony or something that pertains to marriage. To recall our definition of adjective it simply means a descriptive word.
“Each country practices different nuptial rites.”
“I was touched by the nuptial vow of Eric and Suzanne.”
“I was assigned to carry the nuptial cord.”
The word “Nuptials” … this is considered as a noun which refers to an entity, state or concept. Nuptials refers to the wedding itself. So when you opt to use the word ‘wedding’ never follow it with the word ‘nuptials’ otherwise you’re committing redundancy. To easily absorb this just remember that ‘wedding’ is replaceable with the word “nuptials’. This word is commonly seen in the invitations.
“Jones - Jackson Nuptials”
Hope this helps!