tetrad

noun
tet·​rad | \ˈte-ˌtrad \

Definition of tetrad 

: a group or arrangement of four: such as

a : a group of four cells produced by the successive divisions of a mother cell a tetrad of spores

b : a group of four synapsed chromatids that become visibly evident in the pachytene stage of meiotic prophase

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Other Words from tetrad

tetradic \ te-​ˈtra-​dik \ adjective

Examples of tetrad in a Sentence

Recent Examples on the Web

At its most technical, a blood moon is a series of four consecutive lunar eclipses or tetrad, which is not the case for the upcoming eclipse. Mika Mckinnon, Smithsonian, "Don’t Miss This Celestial Triplet: a Blue Moon, Supermoon and Lunar Eclipse," 26 Jan. 2018 The blood moon marked the beginning of a tetrad — four consecutive and complete lunar eclipses occurring at six-month intervals — which some see as a prophecy. Sean Rossman, USA TODAY, "World ending Saturday? Here are all the times the world was supposed to end, and didn't," 21 Sep. 2017

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

First Known Use of tetrad

1653, in the meaning defined above

History and Etymology for tetrad

Greek tetrad-, tetras, from tetra-

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Time Traveler for tetrad

The first known use of tetrad was in 1653

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More Definitions for tetrad

tetrad

noun
tet·​rad | \ˈte-ˌtrad \

Medical Definition of tetrad 

: a group or arrangement of four: as

a : a tetravalent element, atom, or radical

b : a group of four cells arranged usually in the form of a tetrahedron and produced by the successive divisions of a mother cell a tetrad of spores

c : a group of four synapsed chromatids that become visibly evident in the pachytene stage of meiotic prophase and are produced by the longitudinal splitting of each of two paired homologous chromosomes

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