thorax

noun
tho·​rax | \ ˈthȯr-ˌaks How to pronounce thorax (audio) \
plural thoraxes or thoraces\ ˈthȯr-​ə-​ˌsēz How to pronounce thoraces (audio) \

Definition of thorax

1 : the part of the vertebrate body between the neck and the abdomen If you count the vertebrae in the necks and thoraxes of mice and chickens, you will find that a mouse has seven neck and 13 thoracic vertebrae, a chicken 14 and seven, respectively.— Matt Ridley also : thoracic cavity The thorax is evaluated for fluid at the flanks and for pneumothorax anteriorly. — Christoper L. Moore
2 : the middle of the three chief divisions of the body of an insect Of nearly a million described species of insects, none has a biramous appendage, and nearly all have exactly three pairs of limbs on the thorax.— Stephen Jay Gould This haunting pitch issues from drum tissue stretched over the thorax of the male annual cicada …— Ted Williams also : the corresponding part of a crustacean or an arachnid The brown recluse spider … is brown and has fuzzy body hair and a dark violin- or pear-shaped band on the dorsum of its thorax. — Peter F. Weller

Examples of thorax in a Sentence

Recent Examples on the Web Her speech was interrupted when the other mayfly suddenly clasped her thorax tightly with his front legs. Riane Konc, The New Yorker, "Aesop’s Fables Written After a Bad Breakup," 5 Feb. 2020 Americans gussied up Sawyer’s fly with a peacock herl thorax and various kinds of legs. Morgan Lyle, Field & Stream, "7 Great Trout Flies You Can Tie Using Wild-Game Fur and Feathers," 31 Jan. 2020 The creatures sported seven sections on their thorax—or belly plates–says Paul Selden, a paleontologist at the University of Kansas who was not involved in the research. Rodrigo Pérez Ortega, Science | AAAS, "This is the oldest scorpion known to science," 16 Jan. 2020 His plane plummeted into the Pacific Ocean and Rodgers suffered a broken neck and crushed thorax on impact. Brendan I. Koerner, Wired, "It's a Bird! It's a Plane! The Midair Collisions Menacing Air Travel," 24 Jan. 2020 Then, once a bump begins to protrude from the thorax, the wing genes turn off and a new group of genes takes over to enlarge and sculpt the horn. Erica Tennenhouse, Science | AAAS, "Dung beetles borrowed wing genes to grow their horns," 21 Nov. 2019 In insects, the thorax is made up of three segments, with wings reliably developing on the latter two. Katherine J. Wu, Smithsonian, "Treehoppers’ Bizarre, Wondrous Helmets Use Wing Genes to Grow," 9 Dec. 2019 Their study, published today in Nature Ecology & Evolution, suggests treehopper helmets are indeed bits of thorax, not wings. Katherine J. Wu, Smithsonian, "Treehoppers’ Bizarre, Wondrous Helmets Use Wing Genes to Grow," 9 Dec. 2019 Beetles have horns on their heads and the midregion of their body called the thorax, which is broken into three segments. Erica Tennenhouse, Science | AAAS, "Dung beetles borrowed wing genes to grow their horns," 21 Nov. 2019

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'thorax.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of thorax

15th century, in the meaning defined at sense 1

History and Etymology for thorax

Middle English, from Latin thorac-, thorax breastplate, thorax, from Greek thōrak-, thōrax

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Time Traveler for thorax

Time Traveler

The first known use of thorax was in the 15th century

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Statistics for thorax

Last Updated

15 Feb 2020

Cite this Entry

“Thorax.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/thorax?pronunciation&lang=en_us&dir=t&file=thorax01. Accessed 21 Feb. 2020.

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More Definitions for thorax

thorax

noun
How to pronounce thorax (audio)

English Language Learners Definition of thorax

technical
: the part of an animal's body between the neck and the waist
: the middle section of an insect's body

thorax

noun
tho·​rax | \ ˈthȯr-ˌaks How to pronounce thorax (audio) \
plural thoraxes or thoraces\ ˈthȯr-​ə-​ˌsēz \

Kids Definition of thorax

1 : the part of the body of a mammal that lies between the neck and the abdomen and contains the heart and lungs
2 : the middle of the three main divisions of the body of an insect

thorax

noun
tho·​rax | \ ˈthō(ə)r-ˌaks, ˈthȯ(ə)r- How to pronounce thorax (audio) \
plural thoraxes or thoraces\ ˈthōr-​ə-​ˌsēz, ˈthȯr-​ How to pronounce thoraces (audio) \

Medical Definition of thorax

1 : the part of the mammalian body that is situated between the neck and the abdomen and supported by the ribs, costal cartilages, and sternum also : thoracic cavity
2 : the middle of the three chief divisions of the body of an insect also : the corresponding part of a crustacean or an arachnid

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More from Merriam-Webster on thorax

Rhyming Dictionary: Words that rhyme with thorax

Spanish Central: Translation of thorax

Nglish: Translation of thorax for Spanish Speakers

Britannica English: Translation of thorax for Arabic Speakers

Britannica.com: Encyclopedia article about thorax

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