# exoskeleton

/ˌɛksoʊˈskɛɫətən/ (US) · /ˈɛksəʊskˌɛlɪtən/ (UK) · CEFR C1 · Noun

Source: https://englishreference.com/word/exoskeleton
Updated: 2026-10-16

## Definition

a hard outer shell that protects and supports the body of some animals, like insects and crabs. It works like bones on the outside of the body.

For teachers: a rigid external covering that supports and protects the body of certain invertebrates, such as arthropods and molluscs. Contrasts with an internal endoskeleton of the type vertebrates possess.

## Examples

- A beetle has a hard exoskeleton for protection.
- The crab shed its old exoskeleton on the rock and hid until the new shell hardened.
- After molting, the lobster's soft exoskeleton leaves it vulnerable for days while calcium salts gradually harden the new cuticle.

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.