English Reference
noun

anniversary

n.
US /ˌænəˈvɝsɝi/ UK /ˌænɪvˈɜːsəɹˌi/ an·niver·sary UK spelling anniversaries, anniversary's

  1. 01 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.

    Simple

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

    In context

    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.

  2. 02 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.

    Simple

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

    In context

    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.

Also coming up is the three-year anniversary of the Hamas-led attack on southern Israel on 7 October.

The Guardian· 16 Aug 2026

Saturday marks the 5th anniversary of the current Taliban rule in Aghanistan.

NPR· 14 Aug 2026

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

Etymology adapted from Wiktionary, available under CC BY-SA 4.0.

This entry
Origin la-med anniversāria
Level B2 · Upper Intermediate
Frequency Common
Updated