[ mon-ad, moh-nad ]
See synonyms for monad on
  1. Biology.

    • any simple, single-celled organism.

    • any of various small, flagellate, colorless ameboids with one to three flagella, especially of the genus Monas.

  2. Chemistry. an element, atom, or group having a valence of one.: Compare dyad (def. 3), triad (def. 2a).

  1. Philosophy.

    • (in the metaphysics of Leibniz) an unextended, indivisible, and indestructible entity that is the basic or ultimate constituent of the universe and a microcosm of it.

    • (in the philosophy of Giordano Bruno) a basic and irreducible metaphysical unit that is spatially and psychically individuated.

    • any basic metaphysical entity, especially having an autonomous life.

  2. a single unit or entity.

Origin of monad

First recorded in 1605–15; from Late Latin monad- (stem of monas), from Greek monás (stem monád- ) “unity, monad”; see mon-, -ad1

Other words from monad

  • mo·nad·ic [muh-nad-ik], /məˈnæd ɪk/, mo·nad·i·cal, mo·nad·al, adjective
  • mo·nad·i·cal·ly, adverb

Words Nearby monad Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use monad in a sentence

  • The me is a monad, that is, an indivisible unity; of this there can be no doubt.

  • From the monad proceeds an indefinite duad, which is subordinate to the monad as to its cause.

  • Genius watches the monad through all his masks as he performs the metempsychosis of nature.

    Essays, First Series | Ralph Waldo Emerson
  • In short, each monad is a little Leibniz for ever increasing the sum of its knowledge.

    History of Modern Philosophy | Alfred William Benn
  • All this carbon has played its part, and many parts in its time, as animal existences from monad up to man.

    Mistakes of Moses | Robert G. Ingersoll

British Dictionary definitions for monad


/ (ˈmɒnæd, ˈməʊ-) /

  1. plural -ads or -ades (-əˌdiːz) philosophy

    • any fundamental singular metaphysical entity, esp if autonomous

    • (in the metaphysics of Leibnitz) a simple indestructible nonspatial element regarded as the unit of which reality consists

    • (in the pantheistic philosophy of Giordano Bruno) a fundamental metaphysical unit that is spatially extended and psychically aware

  2. a single-celled organism, esp a flagellate protozoan

  1. an atom, ion, or radical with a valency of one

Origin of monad

C17: from Late Latin monas, from Greek: unit, from monos alone
  • Also called (for senses 1, 2): monas

Derived forms of monad

  • monadical, adjective
  • monadically, adverb

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012