• (n.) An instrument for drawing a circular arc without the use of a central point; a cyclograph.
Arc'o·graph noun [ Latin arcus (E. arc ) + -graph .] An instrument for drawing a circular arc without the use of a central point; a cyclograph. 
arcograph 1. An instrument for drawing a circular arc without the use of a central point; a cyclograph. 2. In geometry: An instrument for drawing arcs, having a flexible arc-shaped part adjusted by an extensible straight bar connecting its sides.
an instrument for drawing arcs, having a flexible arc-shaped part adjusted by an extensible straight bar connecting its sides.