tortoise

American  

[tawr-tuhs] / ˈtɔr təs /

noun

1. a turtle, especially a terrestrial turtle.

2. a very slow person or thing.

3. testudo.

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tortoise British  

/ ˈtɔːtəs /

noun

1. any herbivorous terrestrial chelonian reptile of the family Testudinidae, of most warm regions, having a heavy dome-shaped shell and clawed limbs

2. another name for terrapin

3. a slow-moving person

4. another word for testudo See also giant tortoise

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Usage

What’s the difference between a tortoise and a turtle? The words tortoise and turtle are sometimes used interchangeably, and turtle is the more general term. The word tortoise is sometimes used to distinguish a turtle as being a terrestrial (mostly land-dwelling) one, as opposed to an aquatic turtle (one that spends most of its time in water). However, this doesn’t mean that a turtle is necessarily aquatic simply because it’s called a turtle. For example, the box turtle is primarily terrestrial (it can also be called the box tortoise). Turtles and tortoises are both reptiles that belong to the order Testudines. Whether something is called a tortoise or a turtle often depends on its habitat and physical features. Some aquatic turtles, like snapping turtles, have webbed feet, while others, like sea turtles, have flippers. In contrast, turtles that are called tortoises typically have stubby, round feet, and their shells are often more domed. Here are a few quick questions to help you determine whether it’s more appropriate to call something a tortoise or a turtle. Q: Does it spend a lot of time in the water and have webbed feet or flippers?A: It’s probably called a turtle. Q: Does it live mostly on land and have a domed shell and round feet?A: There’s a good chance it’s called a tortoise, but this isn’t always the case. Q: Is it a teenaged, mutant ninja?A: It’s a turtle. Still stumped? Ask a herpetologist. Want to learn more? Read the full breakdown of the difference between tortoises and turtles.

Etymology

Origin of tortoise

1350–1400; variant of earlier (15th-century) tortuse, tortose, tortuce, Middle English tortuca < Medieval Latin tortūca, for Late Latin tartarūcha (feminine adj.) of Tartarus (< Greek tartaroûcha ), the tortoise being regarded as an infernal animal; Medieval Latin form influenced by Latin tortus crooked, twisted ( tort )

Explanation

A tortoise is a reptile with a hard, rounded shell. It's a type of turtle that lives on land all the time — so bring your pet tortoise in the sandbox with you, but not in the pool! A tortoise is a turtle, but a turtle isn't necessarily a tortoise! While most turtles are excellent swimmers and spend much of their time in the water, tortoises are full-time land dwellers. Their shells are more rounded than those of the typical turtle, and they don't have webbed feet. These are adaptations that help tortoises thrive on land, although they are notoriously slow (think "The Tortoise and the Hare").

Example Sentences

An Australian company has launched a rare earths mining project just outside Joshua Tree National Park in critical desert tortoise habitat, an area the company’s director refers to as an “emerging heavy rare earth district.”

From Los Angeles Times • Mar. 30, 2026

Alfie is a pet tortoise who lives on Mrs. Silver’s balcony.

From The Wall Street Journal • Feb. 23, 2026

The reintroduction follows a "back-breeding" programme launched in 2017 after scientists discovered tortoises carrying ancestry of the Floreana giant tortoise on nearby Isabela island.

From BBC • Feb. 21, 2026

Each tortoise underwent an extensive quarantine and was microchipped for identification before their release, it said.

From Barron's • Feb. 20, 2026

In our example on page 41, at every step the tortoise and Achilles get closer and closer to the two-foot mark.

From "Zero: The Biography of a Dangerous Idea" by Charles Seife