noun
Refers broadly to someone who is ill, whether at home or under care. Compared with 患者, it emphasizes the person's being sick rather than their role as a medical patient; the English gloss 'invalid' is old-fashioned and means someone incapacitated by illness.
家に病人がいるので、今日は早く帰ります。
There is a sick person at home, so I will go home early today.
病人を無理に働かせてはいけない。
You must not force a sick person to work.