Arc
'ARC, noun [Latin arcus, a bow, vault or arch; arcuo, to bend; Gr. beginning, origin; to begin, to be the author or chief. The Greek word has a different application, but is probably from the same root as arcus, from the sense of springing or stretching, shooting up, rising, which gives the sense of a vault, or bow, as well as of chief or head. Heb. to weave; to desire, or long for, to ascend. Gr.; Latin fragro; and the sense of arch is from stretching upwards, ascending. From arc or arch comes the sense of bending, deviating and cunning.]
In geometry, any part of the circumference of a circle, or curved line, lying from one point to another; a segment, or part of a circle, not more than a semicircle.