bad blood vs animosity

bad blood and animosity both are nouns.

Word	Noun	Adjective	Verb	Adverb
bad blood	Yes	No	No	No
animosity	Yes	No	No	No

As nouns, bad blood and animosity are synonyms defined as:

bad blood and animosity: a feeling of ill will arousing active hostility

Other synonyms of bad blood include animus.

bad blood (noun)	animosity (noun)
a feeling of ill will arousing active hostility	a feeling of ill will arousing active hostility