tet·​ra | \ ˈte-trə How to pronounce tetra (audio) \

Definition of tetra

 (Entry 1 of 2)

: any of numerous small often brightly colored South American characin fishes often bred in tropical aquariums
variants: or tetr-

Definition of tetra- (Entry 2 of 2)

1 : four : having four : having four parts tetravalent
2 : containing four atoms or groups (of a specified kind) tetrachloride

Examples of tetra in a Sentence

Recent Examples on the Web: Noun

Rob Mendez was born with tetra-amelia syndrome Nothing has ever gotten in the way of Rob Mendez and his dreams. Lindsay Kimble, PEOPLE.com, "Rob Mendez, Football Coach with No Limbs, Aims to Inspire in New Film: 'Focus on What You Can Do'," 28 Aug. 2019 Mendez, as introduced in a 2016 story by this news organization, was born with tetra-amelia syndrome. Gary Peterson, The Mercury News, "Armless, legless South Bay football coach honored at ESPYS has a message for you," 11 July 2019 Mendez was born with the rare disorder tetra-amelia syndrome and was unable to play football growing up despite his passion for the sport. Alaa Abdeldaiem, SI.com, "High School Football Coach Born Without Arms, Legs Wins ESPN's Jimmy V Award," 19 June 2019 Mendez was born with the rare tetra-amelia syndrome, which caused him to be born without arms or legs. Jon Becker, The Mercury News, "South Bay coach born without arms, legs wins ESPN’s Jimmy V Award," 18 June 2019 The queue doubles as an aquarium, and riders follow a twisting route through tanks filled with angelfish, tetras, seahorses, an octopus and seven varieties of rays. Lauren Weber, WSJ, "Roller-Coaster Designer on the Ups and Downs of His Work," 14 June 2019 As space and food decline over the year, and the concentration of predators increases, most of the tetras will die, Dowd says. Harrison Takoff, Smithsonian, "Why You Can Walk Into a Store and Buy a Nearly Extinct Animal," 2 Apr. 2018 In the meantime, the black headwater catfish and silvery Mexican tetras will have the 3.5 million gallon pool all to themselves. John Maccormack, San Antonio Express-News, "Rash of earthquakes prompts fear of oil boom in Balmorhea," 15 June 2018 Mexican tetra swam from surface waters into their caves around 1.5 million years ago. Diana Gitig, Ars Technica, "An evolutionary adaptation that doesn’t directly rely on new mutations," 1 June 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'tetra.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of tetra


1931, in the meaning defined above

History and Etymology for tetra


by shortening from New Latin Tetragonopterus, former genus name, from Late Latin tetragonum quadrangle + Greek pteron wing — more at tetragonal, feather

Combining form

New Latin, from Greek; akin to Greek tettares four — more at four

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Last Updated

1 Sep 2019

Look-up Popularity

Time Traveler for tetra

The first known use of tetra was in 1931

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More from Merriam-Webster on tetra

Britannica.com: Encyclopedia article about tetra

Comments on tetra

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authorized for issue (as a bond)

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