speak vs butterfly

speak is not a noun while butterfly is a noun.

Word	Noun	Adjective	Verb	Adverb
speak	No	No	Yes	No
butterfly	Yes	No	Yes	No

As verbs, butterfly is a hyponym of speak; that is, butterfly is a word with a more specific, narrower meaning than speak:

speak (noun)	butterfly (noun)
	a swimming stroke in which the arms are thrown forward together out of the water while the feet kick up and down
	diurnal insect typically having a slender body with knobbed antennae and broad colorful wings

speak (verb)	butterfly (verb)
express in speech	talk or behave amorously, without serious intentions
exchange thoughts; talk with	cut and spread open, as in preparation for cooking
use language	flutter like a butterfly
give a speech to
make a characteristic or natural sound