atom vs flyspeck

atom and flyspeck both are nouns.

Word	Noun	Adjective	Verb	Adverb
atom	Yes	No	No	No
flyspeck	Yes	Yes	No	No

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

Other hyponyms of atom include grain, grinding, chylomicron, identification particle.

atom (noun)	flyspeck (noun)
(physics and chemistry) the smallest component of an element having the chemical properties of the element	a tiny dark speck made by the excrement of a fly
(nontechnical usage) a tiny piece of anything

atom (adjective)	flyspeck (adjective)
	very small