holy thistle vs lady's thistle

holy thistle and lady's thistle both are nouns.

Word	Noun	Adjective	Verb	Adverb
holy thistle	Yes	No	No	No
lady's thistle	Yes	No	No	No

As nouns, holy thistle and lady's thistle are synonyms defined as:

holy thistle and lady's thistle: tall Old World biennial thistle with large clasping white-blotched leaves and purple flower heads; naturalized in California and South America

Other synonyms of holy thistle include blessed thistle, milk thistle, Our Lady's mild thistle, Silybum marianum.

holy thistle (noun)	lady's thistle (noun)
tall Old World biennial thistle with large clasping white-blotched leaves and purple flower heads; naturalized in California and South America	tall Old World biennial thistle with large clasping white-blotched leaves and purple flower heads; naturalized in California and South America