spiracle

[ spahy-ruh-kuhl, spir-uh- ]

noun

1. a breathing hole; an opening by which a confined space has communication with the outer air; air hole.
2. 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.

spiracle

/ spɪˈrækjʊlə; ˈspaɪərəkəl; ˈspaɪrə- /

noun

1. any of several paired apertures in the cuticle of an insect, by which air enters and leaves the trachea
2. a small paired rudimentary gill slit just behind the head in skates, rays, and related fishes
3. any similar respiratory aperture, such as the blowhole in whales
4. geology a protrusion of sediment into a lava flow, formed by the explosive transition of water into steam

spiracle

/ spĭr′ə-kəl,spī′rə- /

1. 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.

Derived Forms

• spiˈraculate, adjective
• spiracular, adjective

Other Words From

• spi·rac·u·lar [spahy-, rak, -y, uh, -ler, spi-], adjective
• prespi·racu·lar adjective

Word History and Origins

Origin of spiracle¹

1300–50; Middle English < Latin spīrāculum air hole, equivalent to spīrā ( re ) to breathe + -culum -cle ²

Word History and Origins

Origin of spiracle¹

C14 (originally: breath): from Latin spīrāculum vent, from spīrāre to breathe

Example Sentences

The researchers found that when Tiktaalik slid its palate around, its own spiracles would have expanded, perhaps enhancing its ability to breathe air.

From Popular-Science

Small capitate processes or organs, observable under the wings of Diptera, attended by a spiracle.

From Project Gutenberg

The first cleft is no longer similar to the rest, but has commenced to be metamorphosed into the spiracle.

From Project Gutenberg

The external gills project from all the gill-slits including the spiracle.

From Project Gutenberg

But the first has already atrophied considerably, and may easily be recognized as the spiracle.

From Project Gutenberg

Spiracle, spir′a-kl, n. a breathing-hole: any minute passage.

From Project Gutenberg