etch vs aquatint

etch is not a noun while aquatint is a noun.

Word	Noun	Adjective	Verb	Adverb
etch	No	No	Yes	No
aquatint	Yes	No	Yes	No

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

etch (noun)	aquatint (noun)
	a method of etching that imitates the broad washes of a water color
	an etching made by a process that makes it resemble a water color

etch (verb)	aquatint (verb)
selectively dissolve the surface of (a semiconductor or printed circuit) with a solvent, laser, or stream of electrons	etch in aquatint
carve or cut a design or letters into
make an etching of
carve or cut into a block used for printing or print from such a block
cause to stand out or be clearly defined or visible