outpatient vs patient

outpatient and patient both are nouns.

Word	Noun	Adjective	Verb	Adverb
outpatient	Yes	No	No	No
patient	Yes	Yes	No	No

As nouns, patient is a hypernym of outpatient; that is, patient is a word with a broader meaning than outpatient:

outpatient: a patient who does not reside in the hospital where he is being treated
patient: a person who requires medical care

outpatient (noun)	patient (noun)
a patient who does not reside in the hospital where he is being treated	the semantic role of an entity that is not the agent but is directly involved in or affected by the happening denoted by the verb in the clause
	a person who requires medical care

outpatient (adjective)	patient (adjective)
	enduring trying circumstances with even temper or characterized by such endurance