mouse

American  

[mous, mouz] / maʊs, maʊz /

noun

mice plural

1. any of numerous small Old World rodents of the family Muridae, especially of the genus Mus, introduced widely in other parts of the world.

2. any similar small animal of various rodent and marsupial families.

3. a quiet, timid person.

4. Computers. a palm-sized, button-operated pointing device that can be used to move, select, activate, and change items on a computer screen.

5. Informal. a swelling under the eye, caused by a blow or blows; black eye.

6. Slang. a girl or woman.

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verb (used with object)

moused, mousing

1. to hunt out, as a cat hunts out mice.

2. Nautical. to secure with a mousing.

verb (used without object)

moused, mousing

1. to hunt for or catch mice.

2. to prowl about, as if in search of something.

   The burglar moused about for valuables.

3. to seek or search stealthily or watchfully, as if for prey.

4. Computers. to use a mouse to move the cursor on a computer screen to any position.

mouse British  

noun

1. any of numerous small long-tailed rodents of the families Muridae and Cricetidae that are similar to but smaller than rats See also fieldmouse harvest mouse house mouse

2. any of various related rodents, such as the jumping mouse

3. a quiet, timid, or cowardly person

4. computing a hand-held device used to control the cursor movement and select computing functions without keying

5. slang a black eye

6. nautical another word for mousing

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verb

1. to stalk and catch (mice)

2. (intr) to go about stealthily

3. (tr) nautical to secure (a hook) with mousing

mouse Scientific  

/ mous /

1. A hand-held input device that is moved about on a flat surface to direct the cursor on a computer screen. It also has buttons for activating computer functions. The underside of a mechanical mouse contains a rubber-coated ball that rotates as the mouse is moved; optical sensors detect the motion and move the screen pointer correspondingly. An optical mouse is cordless and uses reflections from an LED to track the mouse's movement over a special reflective mat which is marked with a grid that acts as a frame of reference.

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mouse Cultural  

1. A common device that allows the user to reposition an arrow on their computer screen in order to activate desired applications. The term mouse comes from the appearance of the device, with the cord to the main computer being seen as a tail of sorts.

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mouse Idioms  

1. see play cat and mouse; poor as a churchmouse; quiet as a mouse. Also see under mice.

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Discover More

The user usually sends signals to the computer when the user depresses or “clicks” a switch. A number of slang terms, such as “click on X” or “click and drag” have arisen from the appearance of symbols on a screen when a mouse is used.

Other Word Forms

Derived Forms

• mouselike
  adjective

Inflected Forms

noun

• mice
  plural

Etymology

Origin of mouse

before 900; Middle English mous (plural mis ), Old English mūs (plural mȳs ); cognate with German Maus, Old Norse mūs, Latin mūs, Greek mŷs

Explanation

A small rodent with a pointy face, rounded ears, and a long tail is called a mouse. A mouse may be kept as a pet, or it may be an uninvited guest in your home. A person who is timid and shy can also be called a mouse. In computer terms, a mouse is a corded or wireless device that moves your computer's cursor while you move the mouse. In most cases, the plural of mouse is "mice," but more than one computer mouse can also be called "mouses." Mouse can also be a verb in this context, like when you mouse over an icon to select a link.

Example Sentences

It has started tracking employees’ mouse clicks and keystrokes to train its AI models on how to use computers and has touted a future where AI agents primarily do the work and employees supervise them.

From The Wall Street Journal • Jun. 8, 2026

Using both human brain tissue and mouse models of Alzheimer's disease, the ETH Zurich team uncovered evidence that GRK2 may be a major contributor to dementia.

From Science Daily • Jun. 8, 2026

This is a cat and mouse — or cats and mice — melodrama, with customized stock characters given dark secrets and backstory traumas less as explanation than complication.

From Los Angeles Times • Jun. 4, 2026

When the researchers analyzed the human data, they found the same hyperconnectivity and hypoconnectivity patterns identified in the mouse models.

From Science Daily • Jun. 3, 2026

“Get away!” he would say, and he would chase off the cats, the birds, the occasional mouse or rat on the underground.

From "Impossible Creatures" by Katherine Rundell