spiracle

[spahy-ruh-kuh l, spir-uh-]

noun

a breathing hole; an opening by which a confined space has communication with the outer air; air hole.
Zoology.
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 formsspi·rac·u·lar

[spahy-rak-yuh-ler, spi-] /spaɪˈræk yə lər, spɪ-/, adjectivepre·spi·rac·u·lar, adjective

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for spiracle

Historical Examples of 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
Herman Melville
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 common usage the hyomandibular cleft is called the spiracle, and the series of clefts behind it the branchial clefts.
Encyclopaedia Britannica, 11th Edition, Volume 14, Slice 3
Various
In many sharks and in sturgeons the spiracle forms a conspicuous opening just behind the eye.
Encyclopaedia Britannica, 11th Edition, Volume 14, Slice 3
Various

British Dictionary definitions for spiracle

spiracle

noun

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 Formsspiracular (spɪˈrækjʊlə), adjectivespiraculate, adjective

Word Origin for spiracle

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

Word Origin and History for spiracle

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

spiracle in Science

spiracle

[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.