To arc is defined as to make a curved shape or move in a curved path.(verb)
An example of arc is the way stars move across the sky.
The definition of an arc is a curve or bowed shape, like a part of a circle.(noun)
An example of an arc is a rainbow.
See arc in Webster's New World College Dictionary
Origin: ME ark < OFr arc < L arcus, a bow, arch < IE base *arqu-, bowed, curved > arrow
See arc in American Heritage Dictionary 4
Origin: Middle English ark
Origin: , from Old French arc
Origin: , from Latin arcus.
Origin: A(IDS)-r(elated) c(omplex).
Learn more about arc