退院

1. Origins, structure, and basic meaning

• Structure: 退院 (たいいん) is a noun that also forms a する verb for leaving the hospital after a stay or being discharged.
• Basic usage: It is used for a planned hospital discharge or the day on which someone leaves the hospital.
  • 父は来週退院する予定です。 — My father is scheduled to leave the hospital next week.
  • 退院の日に看護師へお礼の手紙を渡した。 — On the day of discharge, I gave the nurse a thank-you letter.

2. Common pitfalls and similar expressions

• Leaving and the discharge day
  • 退院する describes leaving the hospital, while 退院の日 identifies the day it happens. It is directionally opposite to 入院, admission to the hospital.