arch vs curve

arch and curve both are nouns.

Word	Noun	Adjective	Verb	Adverb
arch	Yes	Yes	Yes	No
curve	Yes	No	Yes	No

As nouns, curve is a hypernym of arch; that is, curve is a word with a broader meaning than arch:

Other hypernyms of arch include curved shape.

As verbs, arch and curve are synonyms defined as:

Other synonyms of arch include arc.

arch (noun)	curve (noun)
(architecture) a masonry construction (usually curved) for spanning an opening and supporting the weight above it	a pitch of a baseball that is thrown with spin so that its path curves as it approaches the batter
a passageway under a curved masonry construction	curved segment (of a road or river or railroad track etc.)
a curved bony structure supporting or enclosing organs (especially the inner sides of the feet)	the property possessed by the curving of a line or surface
a curved shape in the vertical plane that spans an opening	a line on a graph representing data
	the trace of a point whose direction of motion changes

arch (adjective)	curve (adjective)
naughtily or annoyingly playful
(used of behavior or attitude) characteristic of those who treat others with condescension

arch (verb)	curve (verb)
form an arch or curve	form a curl, curve, or kink
	turn sharply; change direction abruptly
	form an arch or curve
	bend or cause to bend
	extend in curves and turns