cilium

noun

cil·​i·​um ˈsi-lē-əm 

plural cilia ˈsi-lē-ə 

1

: a minute short hairlike process often forming part of a fringe

especially : one on a cell that is capable of lashing movement and serves especially in free unicellular organisms to produce locomotion or in higher forms a current of fluid

2

: eyelash

Example Sentences

Recent Examples on the Web

One tiny flick of a microscopic cellular hair, known as a cilium, can’t do much on its own. —Saugat Bolakhe, Scientific American, 11 July 2022

Once the voltage is reversed, the oxygen is driven out of the platinum—and the cilium returns to its original shape. —Saugat Bolakhe, Scientific American, 11 July 2022

Mechanical interactions that began at the level of a single cilium, and then multiplied over millions of cells and extended to higher levels of structure, fully explained the coordinated locomotion of the entire animal. —Quanta Magazine, 16 Mar. 2022

Cilia are found throughout our bodies, but only a small number of kinds of cells have more than one cilium apiece. —Caroline Delbert, Popular Mechanics, 30 Dec. 2019

When those cilia become paralyzed, they are rendered unable to do their job protecting the lungs, and this increases your risk of infection, like pneumonia. —Maggie O'neill, Health.com, 12 Sep. 2019

Among their design concerns were methods for nurturing cilium and for recycling sweat. —Guy Trebay, New York Times, 26 Sep. 2017

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Word History

Etymology

New Latin, from Latin, eyelid; akin to Latin celare to conceal — more at hell

First Known Use

1794, in the meaning defined at sense 1

Kids Definition

cilium

noun

cil·​i·​um ˈsil-ē-əm 

plural cilia -ē-ə 

1

: one of the tiny hairlike structures of many cells that make lashing movements

2

: eyelash

Medical Definition

cilium

noun

cil·​i·​um ˈsil-ē-əm 

plural cilia -ē-ə 

1

: eyelash

2

: a minute, short, hairlike process that projects from the surface of most eukaryotic cells, is composed chiefly of microtubules, in unicellular organisms functions chiefly in locomotion, and in higher forms serves especially in the movement of fluids and particles (as the passage of mucus and dust from the lungs) and in sensory reception see ciliopathy