1 the number one; a unit.
2 Philos. any ultimate unit of being (e.g. a soul, an atom, a person, God).
3 Biol. a simple organism, e.g. one assumed as the first in the genealogy of living beings.
Derivatives:
monadic adj. monadism n. (in sense 2).
Etymology: F monade or LL monas monad- f. Gk monas -ados unit f. monos alone
Useful english dictionary. 2012.