a conic projection in which the parallels are arcs of circles that are not concentric but are equally spaced along the central straight meridian, all other meridians being curves equally spaced along the parallels.
Origin of polyconic projection
First recorded in 1900–05
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
a type of conic projection in which the parallels are not concentric and all meridians except the central one are curved lines. It is neither equal-area nor conformal, but is suitable for maps of areas or countries of great longitudinal extent
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012