[spahy-ruh-kuh l, spir-uh-]
- a breathing hole; an opening by which a confined space has communication with the outer air; air hole.
- an aperture or orifice through which air or water passes in the act of respiration, as the blowhole of a cetacean.
- an opening in the head of sharks and rays through which water is drawn and passed over gills.
- 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
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
Examples from the Web for spiracle
Laterostigmatal: situated on the side, immediately above the spiracle.Explanation of Terms Used in Entomology
John. B. Smith
No, he breathes through his spiracle alone; and this is on the top of his head.Moby Dick; or The Whale
H are seen the long filiform external gills which now project out from all the visceral clefts, including the spiracle.The Works of Francis Maitland Balfour, Volume III (of 4)
Francis Maitland Balfour
In many sharks and in sturgeons the spiracle forms a conspicuous opening just behind the eye.
In common usage the hyomandibular cleft is called the spiracle, and the series of clefts behind it the branchial clefts.
- 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
C14 (originally: breath): from Latin spīrāculum vent, from spīrāre to breathe
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
- 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 © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.