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

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

• invertebracy
  noun
• invertebrateness
  noun

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

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

"We are surrounded by some of the rarest animals in the world," says snail keeper Dave Clarke, as we step into a room in the zoo's Tiny Giants invertebrate exhibit.

From BBC • Apr. 28, 2026

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

So the question of cyborg ethics is currently a question of the ethics of creating cyborgs from invertebrate animals.

From Salon • May 13, 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

Related Words

• beast
• creature
• pet