lockup vs jailhouse

lockup and jailhouse both are nouns.

Word	Noun	Adjective	Verb	Adverb
lockup	Yes	No	No	No
jailhouse	Yes	No	No	No

As nouns, jailhouse is a hypernym of lockup; that is, jailhouse is a word with a broader meaning than lockup:

lockup: jail in a local police station
jailhouse: a correctional institution used to detain persons who are in the lawful custody of the government (either accused persons awaiting trial or convicted persons serving a sentence)

Other hypernyms of lockup include clink, gaol, jail, pokey, poky, slammer.

lockup (noun)	jailhouse (noun)
the act of locking something up to protect it	a correctional institution used to detain persons who are in the lawful custody of the government (either accused persons awaiting trial or convicted persons serving a sentence)
jail in a local police station