An arc is part of the circumference of a circle
These words all appear in the definition of the word "rainbow."
-- the current in the arc -- your definition of 'intensity'
The definition of the word island arc is " a curved chain of volcanic islands located at a tectonic plate margin, typically with a deep ocean trench on the convex side."
i dot' know
Arc is a term for caculating the radius
You want a rhyming word arc? Easy it's park.
It is an arc comprising half the circumference.
Curve.
A part of a curved line. Often part of the circumference of a circle, but not necessarily. An arc can refer to other curved line segments.
Arcs, in the same circle or in congruent circles, that have equal measures.
incomplete
Arc would be my best guess. An arc is like the shape of a rainbow.