psychiatric hospital vs mental institution

psychiatric hospital and mental institution both are nouns.

Word	Noun	Adjective	Verb	Adverb
psychiatric hospital	Yes	No	No	No
mental institution	Yes	No	No	No

As nouns, psychiatric hospital and mental institution are synonyms defined as:

psychiatric hospital and mental institution: a hospital for mentally incompetent or unbalanced person

Other synonyms of psychiatric hospital include asylum, insane asylum, institution, mental home, mental hospital.

psychiatric hospital (noun)	mental institution (noun)
a hospital for mentally incompetent or unbalanced person	a hospital for mentally incompetent or unbalanced person