flyspeck vs molecule

flyspeck and molecule both are nouns.

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

As nouns, molecule is a hypernym of flyspeck; that is, molecule is a word with a broader meaning than flyspeck:

Other hypernyms of flyspeck include atom, corpuscle, mote, particle, speck.

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

flyspeck (adjective)	molecule (adjective)
very small