househusband vs house husband

househusband and house husband both are nouns.

Word	Noun	Adjective	Verb	Adverb
househusband	Yes	No	No	No
house husband	Yes	No	No	No

As nouns, househusband and house husband are synonyms defined as:

househusband and house husband: a husband who keeps house while his wife earns the family income

househusband (noun)	house husband (noun)
a husband who keeps house while his wife earns the family income	a husband who keeps house while his wife earns the family income