1. to decline; to go out of use
E.g.: 退化 (degeneration), 衰退 (decline)
2. to retreat; to step back
E.g.: 退却 (retreat), 退場 (exit, leaving)
3. to quit; to step down; to leave
E.g.: 退位 (abdication), 脱退 (withdrawal)
4. to repel; to drive away
E.g.: 退治 (extermination), 撃退 (repulse)
