Definition of spiracle in English:



  • An external respiratory opening, especially each of a number of pores on the body of an insect, or each of a pair of vestigial gill slits behind the eye of a cartilaginous fish.

    • ‘It has long been suggested that insects close the spiracles to prevent desiccation, minimizing water loss but exposing themselves to hypoxic stress.’
    • ‘There is a hole called a spiracle behind each eye.’
    • ‘Catsharks have moderately large spiracles, or respiratory openings, and five pairs of gill slits.’
    • ‘Insects ‘breathe’ through a tracheal system, with external openings called spiracles and increasingly finely branched tubules that carry gases right to the metabolizing tissues.’
    • ‘Its spiracles located behind the eyes allow the guitarfish to remain under the sand for long periods of time and breathe easily by flushing clean water over the gills.’


Late 18th century: from Latin spiraculum, from spirare ‘breathe’.