What does tetra- mean? Tetra- is a combining form used like a prefix meaning “four.” It is used in a great many scientific and other technical terms. In chemistry, tetra- is specifically used to indicate four atoms or four groups of atoms in compounds, e.g., tetrachloride. Tetra- ultimately comes from the Greek téttares, meaning “four.” The name of the classic video game Tetris is based in part on this Greek root. Find out the rest of the story of how Tetris got its name here. The Latin word for “four” is quattor, source of the combining forms quadr-, quadra-, quadri-, and quadru-. Learn about their specific applications in our Words That Use articles for the forms. What are variants of tetra-?When combined with words or word elements that begin with a vowel, tetra- becomes tetr-, as in tetracid.
1930–35; shortening of New Latin Tetragonopterus former genus name. See tetragon, -o-, -pterous
< Greek, combining form of téttara, neuter of téttares four
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To study the evolution of smell-driven behaviours in a laboratory setting, the researchers chose two closely related fish of the Mexican tetra species -- the blind cave-dwelling subtype, and its sighted surface river-dwelling counterpart.
From Science Daily ● Dec. 19, 2023
When floods carried some Mexican tetra river fish, Astyanax mexicanus, into about 30 different caves, other fish of the same species remained at the surface, providing a natural study in contrasting evolutionary paths.
From Washington Post ● Feb. 2, 2023
The banded tetra feeds largely on insects from the terrestrial ecosystem and then excretes phosphorus into the aquatic ecosystem.
From Textbooks ● Sep. 6, 2018
I will not only go to New York and hang out behind the counter and mess with people, but “The Original Soup Man” is now in supermarkets in tetra pack cartons.
From Washington Times ● Jan. 11, 2017
She straightway appeared in miserable plight, “arida, tetra, oculis vagis, ossibus et nervis et pellibus vix hærentibus,” etc.
From Russian Fairy Tales A Choice Collection of Muscovite Folk-lore by Ralston, William Ralston Shedden
The number of NO3 groups which unite with the cellulose molecule under these conditions depends upon the temperature, pressure, etc., employed during the nitration process; di-, tri-, tetra-, penta-, and hexanitrates are all known.
From The Chemistry of Plant Life by Thatcher, Roscoe Wilfred
O, usually divalent, but tetravalent and possibly hexavalent in oxonium and other salts; S, Se, Te, di-, tetra- and hexa-valent; Cr, di-, tri- and hexa-valent; Mo, W, di-, tri-, tetra-, penta- and hexa-valent.
From Encyclopaedia Britannica, 11th Edition, Volume 6, Slice 1 "Châtelet" to "Chicago" by Various
B, trivalent; Al, trivalent, but possibly also tetra- or penta-valent; Ga, divalent and trivalent; In, mono-, di- and tri-valent; Tl, monovalent and trivalent.
From Encyclopaedia Britannica, 11th Edition, Volume 6, Slice 1 "Châtelet" to "Chicago" by Various
This group spans more than 10,000 species, from catfish to aquarium favorites such as tetras and zebrafish.
From Science Daily ● Nov. 3, 2025
I didn’t see the usual darting of neon tetras, and the guppy tanks were all dark.
From "Please Ignore Vera Dietz" by A.S. King
Even the couroucous were invisible, and it seemed likely that the sailor would be obliged to return to that swampy place where he had fished for tetras with such good luck.
From The Mysterious Island by White, Stephen W.
The tetras were tied together by the feet, and Pencroff, happy that they were not returning empty handed, and perceiving that the day was ending, thought it best to return home.
From The Mysterious Island by White, Stephen W.
This done, Pencroff, walking stealthily through the grass, placed one end of his hook-and-line close to the nests of the tetras.
From The Mysterious Island by White, Stephen W.
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
