鈍器

1. Origins, structure, and basic meaning

• Structure: 鈍器 (どんき) is a noun for a hard blunt instrument capable of causing injury.
• Basic usage: 鈍器として使う assigns an ornament that role; 鈍器による傷 identifies a blunt object as the cause of an injury.

2. Common pitfalls and similar expressions

• Role with として and cause with による
  • として describes the function an object serves, whereas による attributes an injury to that instrument.