• 退職たいしょく — retirement
• 退学たいがく — dropping out (of school)
• 退院たいいん — discharge from hospital
• 引退いんたい — retirement (from work/sports)
• 後退こうたい — retreat, falling back

The character 退 combines elements for “leg” and “movement” (辶), symbolizing stepping back or moving away. It appears in many words related to resignation, departure, and rejection. Commonly encountered in both everyday and formal contexts such as school, work, and politics.

彼かれは 会社かいしゃを 退職たいしょくしました。
He retired from the company.

病気びょうきが 治なおって 退院たいいんしました。
I recovered from illness and was discharged from the hospital.

The on-yomi タイ is the standard reading in compound words like 退職, 退院, and 退学. The kun-yomi しりぞく・しりぞける is used in classical or literary contexts and means “to retreat” or “to reject.”