Dictionary.com
definitions

winter cress

noun
  1. any cress belonging to the genus Barbarea, of the mustard family, having lyrate leaves and yellow flowers.

Origin of winter cress

First recorded in 1540–50
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
British Dictionary definitions for wintercress

wintercress

noun
  1. a bitter-tasting yellow-flowered perennial, Barbarea vulgaris, somewhat resembling mustard
  2. a commercial hybrid, Rorippa  ×  sterilis, between watercress and R. microphylla
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