gill slit

noun

1

: any of the openings or clefts between the gill arches in vertebrates that breathe by gills through which water taken in at the mouth passes to the exterior and so bathes the gills

2

: any of the rudimentary grooves in the neck region of the embryos of air-breathing vertebrates that correspond to the gill slits

3

: the external opening to the cavity containing the gills when a protective covering of the gills is present

Examples of gill slit in a Sentence

Recent Examples on the Web

Its gill slits are located within a large circular blotch. —Melissa Cristina Marquez, Forbes, 16 Sep. 2024

The German Darwinist Ernst Haeckel had speculated that while in utero human embryos pass through every stage of evolutionary history, developing first what look like gill slits and tails, which disappear in time. —Maya Jasanoff, The New Yorker, 6 May 2024

Also like other pygmy seahorses, the African species has only one gill slit on its upper back, instead of two below each side of the head, like larger seahorses—another mystery. —National Geographic, 20 May 2020

But to breathe, most pull oxygen-containing water into their mouths and pump it through their gill chambers before expelling it out of their gill slits. —Alex Fox, Science | AAAS, 14 June 2019

Word History

First Known Use

1854, in the meaning defined at sense 1

Kids Definition

gill slit

noun

1

: any of the openings which occur in vertebrates with gills and through which water taken in at the mouth moves to the outside bathing the gills

2

: an undeveloped gill slit that occurs at some time in the development of the embryos of air-breathing vertebrates

Medical Definition

gill slit

noun

: one of the openings or clefts between the gill arches in vertebrates that breathe by gills through which water taken in at the mouth passes to the exterior and bathes the gills

also : branchial cleft