Standard Lemma guide

megayear

noun · 1 senses · updated from the 2026-07-25 local source snapshot

Definitions and examples are grouped by meaning. Pronunciation, history, word forms, translations, descendants, synonyms, antonyms, derived terms, and related words appear whenever the source provides them.

Sound

Pronunciation

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1

noun

Meaning 1

A million years: a thousand thousand years.

Definition source: English Wiktionary via Wiktextract

Examples

  • Holonyms: petasecond < giga-annum, gigayear < exasecond < zettasecond < yottasecond < ronnasecond < quettasecond
  • Meronyms: quectosecond < rontosecond < yoctosecond < zeptosecond < attosecond < femtosecond < picosecond < nanosecond < microsecond < millisecond < centisecond < decisecond < second < decasecond < minute < hectosecond < kilosecond < hour < day < week < megasecond < fortnight < month < year < gigasecond < century < kiloannum, kiloyear, millennium < terasecond

Meaning relationships

Synonyms: Myr, My, mul:Ma, mega-annum, millionennium

Antonyms: none provided

History

Etymology

Etymology tree Proto-Indo-European *méǵh2s Proto-Hellenic *mégas Ancient Greek μέγᾰς (mégăs)der. English mega- Proto-Indo-European *(H)yeh1-der.? Proto-Indo-European *yóh1r̥der. Proto-Germanic *jērą Proto-West Germanic *jār Old English ġēar Middle English yeer English year English megayear From mega- + year.