any weedy North American plant of the genus Triosteum, of the honeysuckle family, especially T. perfoliatum, having stalkless leaves and purplish-brown flowers and bearing orange fruits.
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Origin of horse gentian
An Americanism dating back to 1835–45
Also called tinker's weed.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
British Dictionary definitions for horse gentian
any caprifoliaceous plant of the genus Triosteum, of Asia and North America, having small purplish-brown flowersAlso called: feverwort
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