polyphonic

a. [ Poly- + conic. ] Pertaining to, or based upon, many cones. [ 1913 Webster ]

Polyconic projection (Map Making), a projection of the earth's surface, or any portion thereof, by which each narrow zone is projected upon a conical surface that touches the sphere along this zone, the conical surface being then unrolled. This projection differs from conic projection in that latter assumes but one cone for the whole map. Polyconic projection is that in use in the United States coast and geodetic survey. [ 1913 Webster ]