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heptad

[ hep-tad ]
/ ˈhɛp tæd /
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See synonyms for heptad on Thesaurus.com
noun
the number seven.
a group of seven.
Chemistry. an element, atom, or group having a valence of seven.
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Origin of heptad

First recorded in 1650–60, heptad is from the Greek word heptad- (stem of heptás). See hepta-, -ad1

Words nearby heptad

hepped, Hepplewhite, hepta-, heptachlor, heptachord, heptad, heptadecanoic acid, heptagon, heptagonal, heptahedron, heptahydrate
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

Words related to heptad

hebdomad, septenary, septuplicate

How to use heptad in a sentence

  • But this oddness belongs to other numbers also (pentad, heptad, &c.).

    Aristotle|George Grote

  • Heptad, a term in chemistry to denote an atom that is the equivalent of seven atoms of hydrogen, from hepta, seven.

    The Nuttall Encyclopaedia|Edited by Rev. James Wood

British Dictionary definitions for heptad

heptad
/ (ˈhɛptæd) /
noun
a group or series of seven
the number or sum of seven
an atom or element with a valency of seven

Word Origin for heptad

C17: from Greek heptas seven
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
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