heartsease vs tranquillity

heartsease and tranquillity both are nouns.

Word	Noun	Adjective	Verb	Adverb
heartsease	Yes	No	No	No
tranquillity	Yes	No	No	No

As nouns, tranquillity is a hypernym of heartsease; that is, tranquillity is a word with a broader meaning than heartsease:

Other hypernyms of heartsease include quietness, quietude, tranquility.

heartsease (noun)	tranquillity (noun)
the absence of mental stress or anxiety	a disposition free from stress or emotion
common Old World viola with creamy often violet-tinged flowers	a state of peace and quiet
violet of Pacific coast of North America having white petals tinged with yellow and deep violet	an untroubled state; free from disturbances
a common and long cultivated European herb from which most common garden pansies are derived