Definition of: monad

(mon′ad, mō′nad) noun
1. An indestructible unit; a simple and indivisible substance.
2. A minute, simple, single-celled organism, especially a flagellate infusorian.
3. In metaphysics, the one inseparable spirit in mankind manifesting itself in each person; also, the one inseparable spirit in nature.
—adjective Of, pertaining to, or consisting of a monad: also mo·nad′ic or ·i·cal. [<LL monas, monadis <Gk. monas a unit <monos alone]