billet vs housing

billet and housing both are nouns.

Word	Noun	Adjective	Verb	Adverb
billet	Yes	No	Yes	No
housing	Yes	No	No	No

As nouns, housing is a hypernym of billet; that is, housing is a word with a broader meaning than billet:

Other hypernyms of billet include living accommodations, lodging.

billet (noun)	housing (noun)
lodging for military personnel (especially in a private home)	structures collectively in which people are housed
a short personal letter	a protective cover designed to contain or support a mechanical component
	stable gear consisting of a decorated covering for a horse, especially (formerly) for a warhorse

billet (verb)	housing (verb)
provide housing for (military personnel)