tetra

¹

[ te-truh ]

noun

1. any of several tropical, freshwater fishes of the family Characidae, often kept in aquariums.

tetra-

²

1. a combining form meaning “four,” used in the formation of compound words:

   tetrabranchiate.

tetra-

¹

combining_form

1. four

   tetrameter

tetra

²

/ ˈtɛtrə /

noun

1. any of various brightly coloured tropical freshwater fishes of the genus Hemigrammus and related genera: family Characidae (characins)

Word History and Origins

Origin of tetra¹

1930–35; shortening of New Latin Tetragonopterus former genus name. See tetragon, -o-, -pterous

Origin of tetra²

< Greek, combining form of téttara, neuter of téttares four

Word History and Origins

Origin of tetra¹

from Greek

Origin of tetra²

C20: short for New Latin tetragonopterus (former genus name), from tetragon + -o- + -pterous, from Greek pteron wing

Example Sentences

From a purely environmental standpoint, the statistics in favor of Tetra Pak packaging are astounding.

From The Daily Beast

An ambitious Swiss packaging company, Tetra Pak, presents another alternative to Bag-in-Box.

From The Daily Beast

I had my first taste of Tetra Pak wine from a neon green package labeled “Bandit” a couple of years ago.

From The Daily Beast

In addition, a one-liter Tetra Pak weighs less than a pound.

From The Daily Beast

Eva and her husband Hans Kristian Rausing, heir to the $10bn Tetra Pak fortune, were both friends of Prince Charles.

From The Daily Beast

A small pink flower of the class Tetra dynamia covered the prairie.

From Project Gutenberg

In the case of tetra-substituted compounds, thirty isomers are possible when all the groups are different.

From Project Gutenberg

Sleep may be secured by lowering the blood pressure with half-grain doses of erythrol-tetra-nitrate.

From Project Gutenberg

Fluorescein is readily nitrated, yielding a di- or tetra-nitro compound according to conditions.

From Project Gutenberg

This mixture is treated with potassium chlorate and hydrochloric acid, whereby it is converted into tetra-chlorinated products.

From Project Gutenberg

Words That Use Tetra-

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.

Examples of tetra-

One example of a word you may have encountered that features tetra- is tetragon, “a polygon having four angles or sides,” such as a square or rectangle. A tetragon is also known as a quadrangle or quadrilateral.

The first part of the word, tetra-, means “four,” as we know. The -gon portion of the word may also look familiar: it is a combining form meaning “angled” or “angular,” from the Greek gōnía. Tetragon literally translates to “four-angled.”

The word tetragon comes from the Greek tetrágōnon, which uses the equivalent form of tetra- in the language.

Another geometric shape using the combining form tetra- is tetrahedron, a triangular pyramid; it’s so named because the shape is formed using four (tetra-) faces (-hedron).

You may have also heard of a tetralogy, which refers to a series of four related plays, novels, films, video games, or other media. It’s like a trilogy—plus one. Shakespeare’s so-called Henriad is an example of a tetralogy. It consists of four connected history plays: Richard II, Henry IV, Part 1, Henry IV, Part 2, and Henry V.

What are some words that use the combining form tetra-?

Many of the following words use the equivalent form of tetra- in Greek. 

• tetrabasic
• tetrabrach
• tetracycline
• tetradactyl
• tetrafluoroethylene
• tetragram
• Tetragrammaton
• tetrameter
• tetrapod
• tetrasaccharide
• tetraspore

What are some other forms that tetra- may be commonly confused with?

• tri-
• tetano-
• tera-
• terato-

Break it down!

The combining form -dactyl means “possessing fingers or toes” of the kind specified by the first part of the word. A tetradactyl is an animal with how many toes?