退職
たいしょく · taishoku · JLPT N1 · noun
retirement
🚪 退 = withdraw + 職 = post/job: step back from your post = retirement
退 means retreat or withdraw, and 職 means post or duty, so 退職 is literally withdrawing from one's post. It is also used for resigning from a job, while 定年退職 specifically means retiring at the mandatory age.
退 — walk radical 辶 + 艮 (stop/halt)
退 combines the walking/movement radical 辶 with 艮, which carries a sense of stopping or turning back. Together they depict the action of moving backward or withdrawing. The original sense of retreating or stepping back has remained stable through history.