The plural form of anniversary is anniversaries.

Is there a plural for anniversary?

The plural form of anniversary; more than one (kind of) anniversary.

What is the difference between anniversary and anniversaries?

“Anniversary” has the meaning “year” embedded in it. The word comes from the Latin “annus” which means "year" and “versus,” which means "to turn." So an anniversary marks the turning of a year. ... It's better to say we're celebrating our 12th anniversary instead of our 12-year anniversary.