walk through vs walk-through

walk through is not a noun while walk-through is a noun.

Word	Noun	Adjective	Verb	Adverb
walk through	No	No	Yes	No
walk-through	Yes	No	No	No

walk through (noun)	walk-through (noun)
	a first perfunctory rehearsal of a theatrical production in which actors read their lines from the script and move as directed
	the act of walking in order to view something
	a pedestrian passageway through the ground floor of a building
	a thorough explanation (usually accompanied by a demonstration) of each step in a procedure or process

walk through (verb)	walk-through (verb)
perform in a perfunctory way, as for a first rehearsal