any of several hundred natural compounds, usually of vegetable origin, having a bitter taste, and not admitting of any chemical classification.
Origin of bitter principle
First recorded in 1930–35
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
any of various bitter-tasting substances, such as aloin, usually extracted from plants
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