housing vs lamp housing

housing and lamp housing both are nouns.

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

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

housing: a protective cover designed to contain or support a mechanical component
lamp housing: housing that holds a lamp (as in a movie projector)

housing (noun)	lamp housing (noun)
structures collectively in which people are housed	housing that holds a lamp (as in a movie projector)
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