Firearm vs Gun vs Piece

When to use each in English, with meaning, register, and examples.

Firearm

FormalTop 5,000 (fairly common)C1noun

Gun

Top 1,000 (very common)A2noun

Piece

Top 1,000 (very common)A1noun
Most formal: Firearm
 FirearmGunPiece
Pronunciation🇬🇧 /["/ˈfaɪərɑːm/"]/🇺🇸 /["/ˈfaɪərɑːrm/"]/🇬🇧 /["/ɡʌn/"]/🇺🇸 /["/ɡʌn/"]/🇬🇧 /["/piːs/"]/🇺🇸 /["/piːs/"]/
MeaningA tool that shoots bullets.A tool that shoots bullets.A part of something larger.
ExampleThe police were issued with firearms.The police officer drew his gun to protect himself.Can I have a piece of cake, please?
RegisterFormalNeutralNeutral
How commonTop 5,000 (fairly common)Top 1,000 (very common)Top 1,000 (very common)
CEFR levelC1A2A1
Part of speechnounnounnoun
Collocationsimitation, replica, unlicensed, be in possession of, own, possess, training, enthusiast, expertbig, heavy, loaded, be armed with, carry, have, blaze, fire, go off, control, law, crime, the barrel of a gun, guns and ammunition, hold a gun on somebody, big, heavy, loaded, be armed with, carry, have, blaze, fire, go off, control, law, crime, the barrel of a gun, guns and ammunition, hold a gun on somebodybig, huge, large, assemble, glue (back) together, put (back) together, in pieces, piece of, bits and pieces, break into pieces, smash into pieces, big, huge, large, assemble, glue (back) together, put (back) together, in pieces, piece of, bits and pieces, break into pieces, smash into pieces, big, huge, large, assemble, glue (back) together, put (back) together, in pieces, piece of, bits and pieces, break into pieces, smash into pieces, amazing, beautiful, brilliant, compose, produce, write, be called something, be entitled something, be titled something, piece by, piece for, piece from, a piece of music, a piece of sculpture, a piece of work, amazing, beautiful, brilliant, compose, produce, write, be called something, be entitled something, be titled something, piece by, piece for, piece from, a piece of music, a piece of sculpture, a piece of work, big, huge, large, assemble, glue (back) together, put (back) together, in pieces, piece of, bits and pieces, break into pieces, smash into pieces
Antonymspeace, harmony, calmpeace, disarmamentwhole, complete, entire
Common mistakesConfused with 'firearms' which is the plural form., Using it in informal contexts where 'gun' is appropriate., Incorrectly assuming all firearms are the same.Confusing 'gun' with 'pistol' — not all guns are pistols., Using 'gun' to describe non-firearm weapons, like knives., Mispronouncing the word — some learners may pronounce it as 'gawn' instead of 'gun'.Confused with 'peace'., Used 'pieces' when referring to uncountable nouns incorrectly., Misused as a verb; it is primarily a noun.
Usage notesUse 'firearm' in legal or formal discussions about guns. Avoid in casual conversations where 'gun' is more common.Used in discussions about weapons, hunting, or self-defense. Not appropriate in casual conversations where violence may be discouraged. More accepted in law enforcement or military contexts.Use this word when talking about parts of whole items, such as a piece of cake or a piece of furniture. It is neutral and widely acceptable in both spoken and written contexts.

See it in real clips

Gun
Piece

Frequently asked questions: Firearm vs Gun vs Piece

What's the difference between Firearm, Gun, and Piece?

Firearm: A tool that shoots bullets. Gun: A tool that shoots bullets. Piece: A part of something larger.

Which is more formal: Firearm, Gun, and Piece?

Firearm is the most formal of these.

Which is more advanced: Firearm, Gun, and Piece?

Firearm is the highest level, at C1, on the CEFR scale.

Are Firearm, Gun, and Piece the same CEFR level?

Firearm: C1, Gun: A2, Piece: A1 on the CEFR scale.

What part of speech are Firearm, Gun, and Piece?

Firearm: noun, Gun: noun, Piece: noun.

Can you show an example of each?

Firearm: The police were issued with firearms. Gun: The police officer drew his gun to protect himself. Piece: Can I have a piece of cake, please?

Can I use Firearm, Gun, and Piece interchangeably?

Not always. Firearm, Gun, and Piece are related and overlap in some contexts, but they differ in register, how common they are, and usage, so swapping one for another can change the meaning or tone. Check the differences above before substituting.

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