invertebrate

American  

[in-vur-tuh-brit, -breyt] / ɪnˈvɜr tə brɪt, -ˌbreɪt /

adjective

1. Zoology.

   1. not vertebrate; without a backbone.

   2. of or relating to creatures without a backbone.

2. without strength of character.

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noun

• invertebrates
  plural

1. an invertebrate animal.

2. a person who lacks strength of character.

invertebrate British  

/ ɪnˈvɜːtɪbrɪt, -ˌbreɪt /

noun

1. any animal lacking a backbone, including all species not classified as vertebrates

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adjective

1. of, relating to, or designating invertebrates

invertebrate Scientific  

/ ĭn-vûr′tə-brĭt,-brāt′ /

1. Having no backbone or spinal column.

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1. An animal that has no backbone or spinal column and therefore does not belong to the subphylum Vertebrata of the phylum Chordata. Most animals are invertebrates. Corals, insects, worms, jellyfish, starfish, and snails are invertebrates.

Other Word Forms

Derived Forms

• invertebracy
  noun
• invertebrateness
  noun

Inflected Forms

Nouns

• invertebrates
  plural

Etymology

Origin of invertebrate

From the New Latin word invertebrātus, dating back to 1820–30. See in- ³, vertebrate

Explanation

An invertebrate is an animal without a backbone. Invertebrate animals include fruit flies and sea sponges. Your backbone allows you to stand up straight, and it also allows you to be grouped with the other vertebrates: animals with backbones. Invertebrates are the opposite: they have no backbone. These are the two major groups of animals. Also, this word is used for people who are spineless in the sense of having no courage. You could say a coward acts in an invertebrate way. Whether it's a backbone-free animal or a courage-free person, all invertebrates lack spines.

Example Sentences

See Examples For:

invertebrate invertebrates

The invertebrate paleontology collections overseen by Drs. Cole and Wright at the Oklahoma Museum of Natural History contain more than a million specimens, and additional fossils are added every year.

From Science Daily ● Aug. 21, 2026

However, Ashbrook said true ecological recovery after fires depended on soil fungi returning, plants re-establishing and invertebrate populations recovering, while the loss of mature woodland could take decades to reverse.

From BBC ● Aug. 8, 2026

"So many of the other animals and the plants rely on the invertebrate communities, so they're going to be impacted hugely by that reduction in number," Fisher said.

From BBC ● May 2, 2026

After three years the invertebrate population of that area was still 90% lower.

From BBC ● May 2, 2026

The invertebrate eye was invented into an optical instrument at the MBL, opening the way to modern visual physiology.

From "The Lives of a Cell" by Lewis Thomas

Ground-nesting birds such as hen harriers rely on open, treeless bog, safe from predators that would otherwise perch and watch for prey, while the wet ground breeds the invertebrates chicks are fed on.

From BBC ● Sep. 12, 2026

Rearing the snails - as well as other critically endangered invertebrates such as scarlet malachite beetles, ladybird spiders and tadpole shrimp - has become a family affair.

From BBC ● Sep. 11, 2026

The discovery pushes the story of giant arthropods much further back in time than the period usually associated with enormous insects and other invertebrates.

From Science Daily ● Sep. 2, 2026

The animals, including marine fish, invertebrates and sharks, arrived at the aquarium on June 19, but the aquarium didn’t announce the news until Thursday.

From Los Angeles Times ● Aug. 28, 2026

Offshore, an unfinished break wall was home to kelp beds and invertebrates.

From "The Line Tender" by Kate Allen

Related Words

• beast
• creature
• pet