Quaternary

From Latin quaternārius (“consisting of four”), from quaternī (“by fours”); in numerical sense via Middle English quaternary. Compare French quaternaire.

• enPR: kwŏt′ər-nĕr′ē, kwə-tûr′nə-rē
• (General American) IPA^(key): /ˈkwɑt.əɹˌnɛɹ.i/, /kwəˈtɜɹ.nə.ɹi/
• (Received Pronunciation) IPA^(key): (rare) /ˈkwɒt.əˌnɛɹ.iː/, /kwəˈtɜː.nə.ɹiː/

Quaternary

1. (geology) The geological period of the Cenozoic Era immediately following the Tertiary. It is subdivided into the Pleistocene and the Holocene Epochs.
2. Alternative letter-case form of quaternary.

• Neogene
• Tertiary

• “Quaternary”, in The American Heritage Dictionary of the English Language, 5th edition, Boston, Mass.: Houghton Mifflin Harcourt, 2016, →ISBN.
• “Quaternary”, in The Century Dictionary […], New York, N.Y.: The Century Co., 1911, →OCLC, page 4901, column 2.
• “Quaternary”, in Merriam-Webster Online Dictionary, Springfield, Mass.: Merriam-Webster, 1996–present.
• “Quaternary”, in Webster’s Revised Unabridged Dictionary, Springfield, Mass.: G. & C. Merriam, 1913, →OCLC.
• “Quaternary”, in Lexico, Dictionary.com; Oxford University Press, 2019–2022.
• “Quaternary”, in Cambridge English Dictionary, Cambridge, Cambridgeshire: Cambridge University Press, 1999–present.
• “Quaternary”, in Collins English Dictionary.
• “Quaternary”, in Dictionary.com Unabridged, Dictionary.com, LLC, 1995–present.
• “Quaternary”, in OneLook Dictionary Search.