untruth vs lie

untruth and lie both are nouns.

Word	Noun	Adjective	Verb	Adverb
untruth	Yes	No	No	No
lie	Yes	No	Yes	No

As nouns, lie is a hyponym of untruth; that is, lie is a word with a more specific, narrower meaning than untruth:

untruth (noun)	lie (noun)
a false statement	a statement that deviates from or perverts the truth
	position or manner in which something is situated

untruth (verb)	lie (verb)
	tell an untruth; pretend with intent to deceive
	be lying, be prostrate; be in a horizontal position
	assume a reclining position
	be located or situated somewhere; occupy a certain position
	originate (in)
	have a place in relation to something else
	be and remain in a particular state or condition