love-in-idleness vs viola

love-in-idleness and viola both are nouns.

Word	Noun	Adjective	Verb	Adverb
love-in-idleness	Yes	No	No	No
viola	Yes	No	No	No

As nouns, viola is a hypernym of love-in-idleness; that is, viola is a word with a broader meaning than love-in-idleness:

love-in-idleness: a common and long cultivated European herb from which most common garden pansies are derived
viola: any of the numerous plants of the genus Viola

love-in-idleness (noun)	viola (noun)
a common and long cultivated European herb from which most common garden pansies are derived	any of the numerous plants of the genus Viola
	a bowed stringed instrument slightly larger than a violin, tuned a fifth lower