無断

1. Origins, structure, and basic meaning

• Structure: 無断, read むだん, combines absence 無 with authorization or decision 断 to mark lack of permission.
• Basic usage: It marks acting without permission, as in 無断で持ち出す.

2. Common pitfalls and similar expressions

• Grammar and combinations
  • It also precedes nouns as in 無断欠席 and criticizes omission of required permission or notice, not merely a lack of casual information.