What does "anniversary" mean?

1. (yearly milestone) a day that is exactly one or more years after a special event happened. 2. (non-yearly milestone) a date that marks a specific amount of time since an event, even if it is not a full year.

How do you use "anniversary"?

Often preceded by an ordinal number like 'first', 'tenth', or 'fiftieth'. Requires a time-period modifier, such as 'six-month' or 'one-week'.

anniversary

US //ˌænəˈvɝsɝi// UK //ˌænɪvˈɜːsəɹˌi// an·niver·sary

1 yearly milestone (n.)
B1 Intermediate

a day that is exactly one or more years after a special event happened.

the annual recurrence of a date marking a notable past event, typically a wedding, the founding of an institution, or a historical occurrence.

Example

My parents are celebrating their twenty-fifth wedding anniversary with a big party this weekend.

Example

The university held a series of lectures and gala dinners to commemorate the hundredth anniversary of its founding by the royal charter.

Usage

Often preceded by an ordinal number like 'first', 'tenth', or 'fiftieth'.

Teacher's tip

While 'anniversary' usually implies years, modern speakers sometimes use 'month-anniversary' for shorter periods, though this is informal.
- commemoration
- jubilee
2 non-yearly milestone (n.)
B2 Upper Intermediate Informal

a date that marks a specific amount of time since an event, even if it is not a full year.

a milestone marking a significant period of time other than a year, usually specified by a prefix.

Example

They went out for a nice dinner to celebrate their six-month anniversary of dating.

Example

The startup team marked their one-month anniversary of the product launch by reviewing their initial user growth statistics.

Usage

Requires a time-period modifier, such as 'six-month' or 'one-week'.

Teacher's tip

Strictly speaking, the 'anni-' root means year, but learners will encounter 'month-anniversary' in casual dating or workplace contexts.

Origin

From Middle English anniversary, from Medieval Latin anniversāria (diēs), anniversārium, from anniversārius (“yearly”), from annus (“year”) + versus, past participle of vertere (“to turn”).