武器 (wǔ qì) literally means 'martial tool' — 武 (wǔ) refers to martial arts, warfare, or military matters, while 器 (qì) means 'tool', 'instrument', or 'device'. Together, they form a formal, general term for any object designed or used for combat, defense, or inflicting harm — from ancient swords and bows to modern firearms and missiles. It is a neutral, standard noun used in news reports, historical texts, legal documents, and military contexts.

The word carries no inherent moral judgment but often appears in serious or official discourse — for example, when discussing arms control, self-defense laws, or historical warfare. It is not used for everyday objects repurposed as weapons (e.g., a chair used to strike someone), nor for metaphorical 'weapons' like 'weapons of mass persuasion' — those require different phrasing (e.g., 工具 or 手段). It’s more formal than colloquial alternatives like 枪 (qiāng, 'gun') or 刀 (dāo, 'knife'), which name specific items.