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[spahy-ruh-kuh l, spir-uh-] /ˈspaɪ rə kəl, ˈspɪr ə-/
a breathing hole; an opening by which a confined space has communication with the outer air; air hole.
  1. an aperture or orifice through which air or water passes in the act of respiration, as the blowhole of a cetacean.
  2. an opening in the head of sharks and rays through which water is drawn and passed over gills.
  3. one of the external orifices of the tracheal respiratory system of certain invertebrates, usually on the sides of the body.
Origin of spiracle
1300-50; Middle English < Latin spīrāculum air hole, equivalent to spīrā(re) to breathe + -culum -cle2
Related forms
[spahy-rak-yuh-ler, spi-] /spaɪˈræk yə lər, spɪ-/ (Show IPA),
prespiracular, adjective Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2015.
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Examples from the web for spiracle
  • No spiracle, the small round hole found above the eye in lake sturgeon.
  • Each side of the prothorax has a spiracle, which is an opening of the respiratory system.
  • The spiracle is on the left side of the body and the vent is medial at the tail-body juncture.
British Dictionary definitions for spiracle


/ˈspaɪərəkəl; ˈspaɪrə-/
any of several paired apertures in the cuticle of an insect, by which air enters and leaves the trachea
a small paired rudimentary gill slit just behind the head in skates, rays, and related fishes
any similar respiratory aperture, such as the blowhole in whales
(geology) a protrusion of sediment into a lava flow, formed by the explosive transition of water into steam
Derived Forms
spiracular (spɪˈrækjʊlə) adjective
spiraculate, adjective
Word Origin
C14 (originally: breath): from Latin spīrāculum vent, from spīrāre to breathe
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
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Word Origin and History for spiracle

"air hole," 1610s, from Latin spiraculum, from spirare "to breathe" (see spirit (n.)).

Online Etymology Dictionary, © 2010 Douglas Harper
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spiracle in Science
  (spĭr'ə-kəl, spī'rə-)   
An opening through which certain animals breathe, such as the blowhole of a whale or one of the openings in the exoskeleton of an insect.
The American Heritage® Science Dictionary
Copyright © 2002. Published by Houghton Mifflin. All rights reserved.
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