noun
outpatient
Refers to a patient who visits a hospital or clinic for treatment without being admitted overnight.
この病院は外来患者の受け付けを午前中に行っている。
This hospital accepts outpatients in the morning.
入院患者 means 'inpatient', someone admitted to a hospital for at least one night, contrasting with 外来患者 who visits without overnight stay.
Compound of 外来 (outpatient visit, from 外 'outside' + 来 'come') and 患者 (patient).