The word "curve" can function as both a noun and a verb. As a noun, it refers to a smooth, continuous line that bends without angles. As a verb, it means to bend or shape something into a curve. The part of speech depends on how it is used in a sentence.
If the curve is part of the circumference of the circle, it is called an arc.
An arc is part of the circumference of a circle
noun
Circumference is a noun.
"Ellipse" is a noun.
verb
It is an action verb.
The part of speech for this particular word is a noun.
part of speech
The part of speech for "answer" is a noun.
what part of speech is beneath
adverb
im not sure
a curve.
The part of speech for "explicit" is an adjective.
The part of speech for "lecturer" is a noun.
The part of speech for "rapid" is an adjective.