thief

American  

[theef] / θif /

noun

plural

thieves

1. a person who steals, especially secretly or without open force; one guilty of theft or larceny.

   Synonyms:

   highwayman, pickpocket, burglar

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thief British  

/ θiːf /

noun

1. a person who steals something from another

2. criminal law a person who commits theft

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Usage

What does thief mean? A thief is a person who steals, especially in secret and without using force or violence. The plural of thief is thieves. The related noun theft refers to the act or an instance of stealing. In general, intentionally taking something that doesn’t belong to you makes you a thief. The word most commonly refers to a person who steals money or physical property, but a thief can steal other things, such as ideas, information, or intellectual property. The word thief typically refers to a person who steals without anyone noticing, at least not when the theft is taking place. In contrast, a person who steals by using force, violence, or threats of force or violence would more likely be called a robber. Still, the word thief is used generally to refer to someone who steals. In this way, a robber is a kind of thief. Most instances of theft are crimes, but a person might still be called a thief if they’ve committed a theft that won’t get them arrested. You might call your sibling a thief when they steal a cookie from your plate, for example. Example: I don’t care that he only stole a few things—he stole them, and that makes him a thief.

Related Words

Thief, robber refer to one who steals. A thief takes the goods or property of another by stealth without the latter's knowledge: like a thief in the night. A robber trespasses upon the house, property, or person of another, and makes away with things of value, even at the cost of violence: A robber held up two women on the street.

Other Word Forms

• thievish adjective
• thievishly adverb
• thievishness noun
• underthief noun

Etymology

Origin of thief

First recorded before 900; Middle English; Old English thēof; cognate with Dutch dief, German Dieb, Old Norse thjōfr, Gothic thiufs

Explanation

A thief is someone who steals something. A thief can be anything from a cyberspace criminal mastermind who steals credit card information around the world, to the petty thief who picks people's pockets on the subway. Some famous thieves (notice the -v- in the plural) include outlaws of the Old West, like Butch Cassidy and Jesse James, and those notorious bank robbers of the 1930s with the memorable names — "Baby Face" Nelson, "Pretty Boy" Floyd, Bonnie and Clyde, Ma Barker, "Machine Gun" Kelly, to name a few. They were so bold (and so brutal) that their activities became a major impetus for the beefing up of the FBI, under J. Edgar Hoover.

Example Sentences

An "opportunistic" thief who stole a handbag containing an emerald-encrusted Fabergé egg and watch set worth up to £2.2 million from a central London pub has been jailed for more than two years.

From BBC • Apr. 9, 2026

Systems are imperfect and mistakes happen, meaning “there is an intrinsic risk” that a thief will steal your sensitive data, Schwartz says.

From The Wall Street Journal • Mar. 20, 2026

Next year’s “Gatto,” about a feline thief in Venice, features animal fur and human hair that look like they were painted by hand, rather than a computer trying to simulate the real thing.

From The Wall Street Journal • Mar. 7, 2026

I would pry them off with my fingers and eat them standing at the stove, like a tiny kitchen thief.

From Salon • Feb. 24, 2026

Plug in your adjectives and get your thief.

From "The Mona Lisa Vanishes" by Nicholas Day

Related Words

• bandit
• burglar
• criminal
• crook
• mugger
• pickpocket
• pirate
• robber
• sniper
• swindler