ceph·​a·​lo·​tho·​rax ˌse-fə-lə-ˈthȯr-ˌaks How to pronounce cephalothorax (audio)
: the united head and thorax of an arachnid or higher crustacean

Examples of cephalothorax in a Sentence

Recent Examples on the Web Their ridged cephalothorax, four pairs of legs and sharp mouth-parts may be seen. Rebecca Kreston, Discover Magazine, 18 Apr. 2011 Opillonids, also called harvestmen, consist of one basic body segment — plus legs — while spiders have two main body parts: the cephalothorax and abdomen. Fox News, 3 Jan. 2014 During the molting process, tarantulas contract their abdomens, which pushes fluid into the upper body, or cephalothorax. National Geographic, 24 May 2017

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'cephalothorax.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History


International Scientific Vocabulary

First Known Use

1835, in the meaning defined above

Time Traveler
The first known use of cephalothorax was in 1835

Dictionary Entries Near cephalothorax

Cite this Entry

“Cephalothorax.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/cephalothorax. Accessed 29 Feb. 2024.

Kids Definition


ceph·​a·​lo·​tho·​rax ˌsef-ə-lə-ˈthō(ə)r-ˌaks How to pronounce cephalothorax (audio)
: a combined head and thorax (as of a spider or crab)

Medical Definition


ceph·​a·​lo·​tho·​rax ˌsef-ə-lə-ˈthō(ə)r-ˌaks, -ˈthȯ(ə)r- How to pronounce cephalothorax (audio)
: the united head and thorax of an arachnid or higher crustacean

More from Merriam-Webster on cephalothorax

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