live-forever vs livelong

live-forever and livelong both are nouns.

Word	Noun	Adjective	Verb	Adverb
live-forever	Yes	No	No	No
livelong	Yes	Yes	No	No

As nouns, live-forever and livelong are synonyms defined as:

live-forever and livelong: perennial northern temperate plant with toothed leaves and heads of small purplish-white flowers

Other synonyms of live-forever include orpin, orpine, Sedum telephium.

live-forever (noun)	livelong (noun)
perennial northern temperate plant with toothed leaves and heads of small purplish-white flowers	perennial northern temperate plant with toothed leaves and heads of small purplish-white flowers

live-forever (adjective)	livelong (adjective)
	(of time) constituting the full extent or duration