immure vs lag

immure is not a noun while lag is a noun.

Word	Noun	Adjective	Verb	Adverb
immure	No	No	Yes	No
lag	Yes	No	Yes	No

As verbs, immure and lag are synonyms defined as:

Other synonyms of immure include gaol, imprison, incarcerate, jail, jug, put away, put behind bars, remand.

immure (noun)	lag (noun)
	the act of slowing down or falling behind
	one of several thin slats of wood forming the sides of a barrel or bucket
	the time between one event, process, or period and another

immure (verb)	lag (verb)
lock up or confine, in or as in a jail	throw or pitch at a mark, as with coins
	cover with lagging to prevent heat loss
	hang (back) or fall (behind) in movement, progress, development, etc.
	lock up or confine, in or as in a jail