1 vs monad

1 and monad both are nouns.

Word	Noun	Adjective	Verb	Adverb
1	Yes	Yes	No	No
monad	Yes	No	No	No

As nouns, monad is a hyponym of 1; that is, monad is a word with a more specific, narrower meaning than 1:

1: the smallest whole number or a numeral representing this number
monad: a singular metaphysical entity from which material properties are said to derive

Other hyponyms of 1 include monas, singleton.

1 (noun)	monad (noun)
the smallest whole number or a numeral representing this number	(biology) a single-celled microorganism (especially a flagellate protozoan)
	a singular metaphysical entity from which material properties are said to derive
	(chemistry) an atom having a valence of one

1 (adjective)	monad (adjective)
used of a single unit or thing; not two or more