milk thistle

Noun

• tall Old World biennial thistle with large clasping white-blotched leaves and purple flower heads; naturalized in California and South America

• any of several Old World coarse prickly-leaved shrubs and subshrubs having milky juice and yellow flowers; widely naturalized; often noxious weeds in cultivated soil

Related words

• Synonyms: 
  lady's thistle , Our Lady's mild thistle , holy thistle , blessed thistle , Silybum marianum , sow thistle