applier vs paintbrush

applier and paintbrush both are nouns.

Word	Noun	Adjective	Verb	Adverb
applier	Yes	No	No	No
paintbrush	Yes	No	No	No

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

Other hyponyms of applier include flux applicator, spray gun.

applier (noun)	paintbrush (noun)
a device for applying a substance	a brush used as an applicator (to apply paint)
a person who requests or seeks something such as assistance or employment or admission