Translation guide
The English word 'weapon' covers physical arms, but also metaphorical tools used to gain advantage. In Japanese, the core word is 武器 (buki), but the best choice depends on context: physical weapons, abstract weapons, or idiomatic expressions.
A tool designed to inflict harm or used in combat, such as a sword, gun, or knife.
The most common and general term for any physical weapon. Used in everyday conversation, news, and formal contexts.
He was carrying a concealed weapon.
警察は凶器として使用された武器を押収した。
The police seized the weapon used in the crime.
Refers to military weapons, arms, or ordnance. Used for large-scale or military contexts like missiles, tanks, or chemical weapons.
核兵器の廃絶を訴える。
They advocate the abolition of nuclear weapons.
この国は大量破壊兵器を保有している。
This country possesses weapons of mass destruction.
Specifically a weapon used in a crime or an assault. Often appears in police reports or news about violent incidents.
犯人は凶器として包丁を使った。
The culprit used a kitchen knife as the weapon.
An archaic or literary term for one's weapon of choice, often a sword or spear. Used in historical dramas or fantasy.
侍は得物を手に戦いに臨んだ。
The samurai faced battle with his weapon in hand.
Something used to gain an advantage or to attack someone non-physically, like charm, intelligence, or information.
Also used metaphorically for any skill, trait, or tool that gives an advantage. Very common in business, sports, and personal contexts.
彼の最大の武器は語学力だ。
His greatest weapon is his language ability.
笑顔は最強の武器だ。
A smile is the most powerful weapon.
Literally 'trump card', used for a secret weapon or a decisive resource held in reserve.
Common phrases where 'weapon' appears in English but may have a different natural Japanese equivalent.
Means 'double-edged sword', used when something can be both beneficial and harmful.
インターネットは諸刃の剣だ。
The internet is a double-edged weapon.
兵器 (heiki) is strictly for military arms. Using it for a knife or a personal weapon sounds unnatural. Stick to 武器 (buki) for general use.
武器 is a neutral term for any weapon. 凶器 specifically implies a weapon used in a crime or violent act, similar to 'murder weapon' or 'deadly weapon' in English.
彼は魅力を武器にした。
He used his charm as a weapon.
彼は最後の切り札を出した。
He played his final weapon (trump card).
Literally 'family heirloom sword', used for a last resort or a rarely used but powerful measure.
社長は伝家の宝刀を抜いた。
The president brought out his ultimate weapon.