mitosis

noun

mi·​to·​sis mī-ˈtō-səs How to pronounce mitosis (audio)
plural mitoses mī-ˈtō-ˌsēz How to pronounce mitosis (audio)
1
: a process that takes place in the nucleus of a dividing cell, involves typically a series of steps consisting of prophase, metaphase, anaphase, and telophase, and results in the formation of two new nuclei each having the same number of chromosomes as the parent nucleus compare meiosis
2
: cell division in which mitosis occurs

Examples of mitosis in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Ed was, after all, already creating the Cells series, looking at mitosis and immune response through a visual vocabulary shaped by Japanese woodblock design. Emilie Hardman, JSTOR Daily, 6 May 2026 Perhaps that’s the next phase of Coachella’s mitosis: Weekend 1 determines how Coachella is seen, and Weekend 2 is where that attention is extended, maybe even reshaped. Andrea Domanick, Los Angeles Times, 26 Apr. 2026 The cancellation comes as NBCUniversal’s brands undergo mitosis. Jason P. Frank, Vulture, 24 July 2025 Perhaps her past has undergone enough mitosis to morph into future originality. Rachel Syme, The New Yorker, 12 Mar. 2025 See All Example Sentences for mitosis

Word History

Etymology

borrowed from German Mitosis (later Mitose), from Greek mítos "length of thread, cord used to separate warp threads" (of uncertain origin) + -ōsis -osis

Note: Term coined by the German biologist Walther Flemming (1843-1905) in Zellsubstanz, Kern und Zelltheilung (Leipzig, 1882), p. 376. Flemming introduces the word first in the compound Karyomitosis as a replacement for Karyokinesis to denote specifically "the metamorphosis of threads in the nucleus" ("Fadenmetamorphose im Kern"). In following sentences he uses the truncated form in the plural Mitosen for mitotic figures ("Kerntheilungsfiguren," i.e, the spindle-shaped figures presented by the chromosomes during mitosis) and in the singular Mitosis for the process of division.

First Known Use

1887, in the meaning defined at sense 1

Time Traveler
The first known use of mitosis was in 1887

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Cite this Entry

“Mitosis.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/mitosis. Accessed 13 May. 2026.

Kids Definition

mitosis

noun
mi·​to·​sis mī-ˈtō-səs How to pronounce mitosis (audio)
plural mitoses -ˈtō-ˌsēz How to pronounce mitosis (audio)
1
: a process that takes place in the nucleus of a dividing cell and that results in the formation of two new nuclei with the same number of chromosomes as the parent nucleus compare meiosis
2
: a cell division in which mitosis occurs
mitotic adjective

Medical Definition

mitosis

noun
mi·​to·​sis mī-ˈtō-səs How to pronounce mitosis (audio)
plural mitoses -ˌsēz How to pronounce mitosis (audio)
1
: a process that takes place in the nucleus of a dividing cell, involves typically a series of steps consisting of prophase, metaphase, anaphase, and telophase, and results in the formation of two new nuclei each having the same number of chromosomes as the parent nucleus compare meiosis
2
: cell division in which mitosis occurs
mitotic adjective
mitotically adverb

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