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
Derived forms
spiracular (spɪˈrækjʊlə)
adjective
spiraculate (spiˈraculate)
adjective
Word origin
C14 (originally: breath): from Latin spīrāculum vent, from spīrāre to breathe
spiracle in American English
(ˈspɪrəkəl; ˈspaɪrəkəl)
noun
1.
a small opening allowing the outer air to come through into a confined space; air hole
2. Geology
a small vent formed on the surface of a thick lava flow
3. Zoology
an aperture for breathing, as
a.
any of the small external openings of the tracheal respiratory system in most terrestrial arthropods, ordinarily along the sides of certain thoracic and abdominal segments; stigma
b.
any of various similar openings for the passage of air or respiratory water, as intadpoles