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  

/ -ˌbreɪt, ɪnˈvɜːtɪbrɪt /

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

It is believed to be home to more than 100 plant species and rich invertebrate fauna, and is recognised as one of the most important chalk river habitats in England.

From BBC ● Aug. 2, 2026

Some campaigners describe the site as an "incomparable haven" for nature, with more than 1,000 invertebrate species found there - including at least 99 of conservation concern.

From BBC ● May 3, 2026

The findings address a long-standing gap in understanding how both vertebrate and invertebrate eyes continue growing and sustaining themselves.

From Science Daily ● Dec. 2, 2025

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

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

The Assn. of Zoos and Aquariums Wildlife Confiscations Network was notified about a box truck filled with more than 2,000 animals, including fish, reptiles, invertebrates and amphibians, according to the release.

From Los Angeles Times ● Aug. 28, 2026

But McLaren, who lives near the coast in North Ayrshire, believes there is more to the brainless, heartless and boneless invertebrates than people might think.

From BBC ● Jul. 28, 2026

Bates said many discoveries from fruit fly neuroscience have carried over from invertebrates to mammals, including findings related to navigation, olfaction, and memory.

From Science Daily ● Jun. 10, 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