gun

Compared meaning: a weapon that fires bullets or shells (noun).

比较义项：能发射弹药的枪炮类武器（名词）。

• gun 本词

  The general, everyday word for any weapon that fires bullets or shells, from a small handgun to a large cannon; it is countable and used in both civilian and military contexts.

  gun 是最普通、最常用的词，泛指任何能发射子弹或炮弹的武器，小到手枪、大到火炮都可以；它是可数名词，既可用于平民语境，也可用于军事语境。

  The police officer kept his gun holstered during the parade.

  这名警察在游行期间把枪一直配在枪套里。

• artillery

  Refers only to large, heavy guns used collectively by an army; it is an uncountable collective noun and never describes a handgun or rifle.

  artillery 只指军队集体使用的大型重炮，是不可数的集合名词，绝不用来指手枪或步枪。

  The soldiers moved the heavy artillery closer to the front line.

  士兵们把重型火炮转移到靠近前线的地方。

• ordnance

  A more formal, technical military term covering large guns as well as other weapons, ammunition, and explosive equipment; it is uncountable and often used for bombs or shells that are stored, transported, or defused.

  ordnance 是更正式、更专业的军事术语，除大炮外还包括其他武器、弹药和爆炸装备；它是不可数名词，常用于描述被储存、运输或排除的炸弹或炮弹。

  Soldiers carefully removed the unexploded ordnance from the field.

  士兵们小心翼翼地把未爆炸的军械从场地上清除。

Gun, artillery, and ordnance all name weapons that fire ammunition. Gun is the general word for any size, from a handgun to a cannon. Artillery means large guns used by an army, and is uncountable. Ordnance is a formal term for guns, bombs, and ammunition.

这三个词都表示能发射弹药的武器，但范围和语域不同：gun 是最通用的词，指任何大小的枪炮；artillery 特指军队使用的大型重炮，是不可数的集合名词；ordnance 语域更正式，除大炮外还涵盖炸弹、弹药等军事装备。