脱退

1. Origins, structure, and basic meaning

• Structure: 脱退 (だったい) combines leaving 脱 and withdrawing 退 to denote formal withdrawal from a group or federation.
• Basic usage: It applies to members leaving an organization and an organization deciding to secede from an alliance.

2. Common pitfalls and similar expressions

• Ending membership rather than temporary absence
  • 脱退する terminates the affiliation and is stronger than simply missing an activity or taking a short break.