Pŏl'y-cŏn'ic, a.

a. [Gr. πολὺς, many, and κῶνος, cone.] Pertaining to, or based upon, many cones; as, a polyconic projection.

Polyconic projection (Map Projection), a projection or development of the earth's surface, or a portion of it, which supposes each parallel of latitude represented on a plane by the development of a cone having the parallel for its base and its vertex in the point where a tangent at the parallel intersects the earth's axis. This projection differs from the conic in supposing a different cone of projection for each parallel, while the latter assumes but one cone for the whole map. It is the one used in the United States coast survey.