bear's breeches vs Acanthus mollis

bear's breeches and Acanthus mollis both are nouns.

Word	Noun	Adjective	Verb	Adverb
bear's breeches	Yes	No	No	No
Acanthus mollis	Yes	No	No	No

As nouns, bear's breeches and Acanthus mollis are synonyms defined as:

bear's breeches and Acanthus mollis: widely cultivated southern European acanthus with whitish purple-veined flowers

Other synonyms of bear's breeches include bear's breech, sea holly.

bear's breeches (noun)	Acanthus mollis (noun)
widely cultivated southern European acanthus with whitish purple-veined flowers	widely cultivated southern European acanthus with whitish purple-veined flowers