1. (noun)
milk thistle, lady's thistle, Our Lady's mild thistle, holy thistle, blessed thistle, Silybum marianum
- tall Old World biennial thistle with large clasping white-blotched leaves and purple flower heads; naturalized in California and South America Synonyms: lady's thistle, milkthistle, sow thistle, blessed thistle, holythistle, sweetsultan