anniversary

/ˌænɪˈvɜːs(ə)ɹi/noun

The date each year that marks an exact number of years since an important event took place.

Example sentence

“They celebrate their wedding anniversary every June.”

Built on the Latin for "year", so a "six-month anniversary" is loose usage. Unmodified, it usually means a wedding anniversary.

Related words

widowerA man whose wife or spouse has died and who has not remarried; the male counterpart of a widow.honeymoonThe holiday or stretch of time that a couple enjoys right after getting married.bachelorA man who could marry but has not yet done so.engagementThe state of being interested and involved in something, feeling drawn in and curious about what comes next.spinsterAn older woman who has never married, especially one considered past the usual age for marriage.fianceTo promise someone in marriage; to engage or betroth.