molecule vs flyspeck

molecule and flyspeck both are nouns.

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

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

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

molecule (noun)	flyspeck (noun)
(physics and chemistry) the simplest structural unit of an element or compound	a tiny dark speck made by the excrement of a fly
(nontechnical usage) a tiny piece of anything

molecule (adjective)	flyspeck (adjective)
	very small