arc
1. arc \'a:rk\ n [ME ark, fr. MF arc bow, fr. L arcus bow, arch, arc -
more]at ARROW 1: the apparent path described above and below the horizon by
the sun or ot her celestial body 2: something arched or curved; esp : a
sustained luminous discharge of electricity gap in a circuit or between
electrodes 3: a continuous portion of a circle or other curve
2. arc vi 1: to form an electric arc 2: to follow an arc-shaped course
3. arc aj [arc sine arc or angle (corresponding to the) sine (of so many
degrees)] : INVERSE {~ sine}