disparagement vs gadfly

disparagement and gadfly both are nouns.

Word	Noun	Adjective	Verb	Adverb
disparagement	Yes	No	No	No
gadfly	Yes	No	No	No

disparagement (noun)	gadfly (noun)
the act of speaking contemptuously of	any of various large flies that annoy livestock
a communication that belittles somebody or something	a persistently annoying person