trigon [trahy-gon] EXAMPLES|WORD ORIGIN noun a triangle. an ancient Greek stringed instrument with a triangular shape. Astrology Archaic.
Origin of trigon 1555–65; Latin trigōnum triangle Greek trígōnon, noun use of neuter of trígōnos three-angled. See, trigon. Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019 Examples from the Web for trigon Historical Examples of trigon
Thus we speak of a pentagon but not of a tetragon or a trigon, although both words are correct in form.
David Eugene Smith
British Dictionary definitions for trigon trigon noun (in classical Greece or Rome) a triangular harp or lyre an archaic word forWord Origin for trigon C17: via Latin from Greek trigōnon triangle. See tri-, -gon 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