outpatients

outpatients は out-「外」+ patients「患者」なので、病院に泊まらず外から来て診療を受け、治療後は帰る患者たちと覚えるとよいです。反対語の inpatients は入院患者で、in と out の向きの違いがそのまま意味の違いになります。病院の掲示や分類では outpatient department「外来部門」、outpatient clinic「外来診療所」、treat outpatients「外来患者を診る」のように使われます。

Remember it as the opposite of `inpatients`. If an `inpatient` stays in the hospital, an `outpatient` comes for care and then goes out again. The prefix `out-` gives the direction and makes the word easy to remember. You will often see it in hospital phrases like `outpatient clinic` and `treat outpatients`.