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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.


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

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

adjective

  1. of, relating to, or designating invertebrates

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
invertebrate Scientific  
/ ĭn-vûrtə-brĭt,-brāt′ /
  1. Having no backbone or spinal column.


  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

Inflected Forms

Nouns

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.

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Vocabulary lists containing invertebrate

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

See Examples For:

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

From BBC May 2, 2026

One species has been successfully reintroduced to its Polynesian island home – the first invertebrate ever to be downlisted from extinct in the wild to critically endangered.

From BBC Apr. 28, 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

In the second major Ocean Species Discoveries collection, more than 20 researchers collaborated to describe 14 new marine invertebrate species and two new genera from across the globe.

From Science Daily Nov. 2, 2025

In organic chemistry, invertebrate zoology, and the inspired symmetry of Mendelian genetics, I have found a religion that serves.

From "The Poisonwood Bible" by Barbara Kingsolver

Spiders belong to a large group of invertebrates called chelicerates, which also includes scorpions and ticks.

From Science Daily Aug. 4, 2026

But we show that if you could identify it, you’d have a level playing field to compare humans, invertebrates, and computers.

From Science Daily Jun. 5, 2026

Space4Nature said some 350 volunteers had been trained in ecological surveys for both invertebrates and vegetation.

From BBC Jun. 4, 2026

The species was found living on bryozoans, tiny aquatic invertebrates commonly known as "moss animals."

From Science Daily May 27, 2026

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

From "The Line Tender" by Kate Allen

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