1. a North American composite weed, Erigeron canadensis, having narrow, hairy leaves and clusters of very small greenish-white flowers.
  2. horse balm.
  3. any of various other common weeds with small yellow flowers.

Origin of horseweed

An Americanism dating back to 1780–90; horse + weed1 Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for horseweed

Historical Examples of horseweed

  • He came out upon the road slowly and stopped there, switching his legs absently with the stalk of a horseweed.

British Dictionary definitions for horseweed


  1. the US name for Canadian fleabaneSee fleabane (def. 3)
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