thistle definition
thistle in American English (ËÎ¸ÉªsÉl ; t hisËÉl) noun. any of various plants (as genera Onopordum, Cirsium, and Cnicus) of the composite family, with prickly leaves and heads of white, purple, pink, or yellow flowers; esp., the Scotch thistle (O. acanthium) with white down and lavender flowers.