- a unit; something simple and indivisible
- any simple, single-celled organism, specif., a simple type of flagellated protozoan or protist
- any of the four nuclei formed at the completion of meiosis
- Chem. a monovalent atom, element, or radical
- Philos. an entity or elementary being thought of as a microcosm or ultimate unit
Origin of monadLate Latin monas (gen. monadis) ; from Classical Greek monas (gen. monados), a unit, unity ; from monos, alone: see mono-
- Philosophy An indivisible, impenetrable unit of substance viewed as the basic constituent element of physical reality in the metaphysics of Leibniz.
- Biology A single-celled microorganism, especially a flagellate protozoan formerly classified in the taxonomic group Monadina.
Origin of monadLatin monas, monad-, unit, from Greek, from monos, single; see men-4 in Indo-European roots.
- mo·nad′ic , mo·nad′i·cal