hexad

American  

[hek-sad] / ˈhɛk sæd /

noun

1. the number six.

2. a group or series of six.

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hexad British  

/ ˈhɛksæd /

noun

1. a group or series of six

2. the number or sum of six

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Other Word Forms

• hexadic adjective

Etymology

Origin of hexad

1650–60; < Late Latin hexad- (stem of hexas ) < Greek hexad- (stem of hexás ) unit of six, equivalent to héx six + -ad- -ad ¹

Example Sentences

Here there is a plane of symmetry perpendicular to the hexad axis; there is also a centre of symmetry.

From Encyclopaedia Britannica, 11th Edition, Volume 7, Slice 7 "Crocoite" to "Cuba" by Various

Owing to the peculiarities of symmetry associated with a single triad or hexad axis, the crystallographic axes of reference are different in this system from those used in the five other systems of crystals.

From Encyclopaedia Britannica, 11th Edition, Volume 7, Slice 7 "Crocoite" to "Cuba" by Various

Six dyad axes of two kinds are perpendicular to the hexad axis.

From Encyclopaedia Britannica, 11th Edition, Volume 7, Slice 7 "Crocoite" to "Cuba" by Various

This is the hexad axis or hexagonal axis, for which the angle of rotation is 60�, or one-sixth of 360�.

From Encyclopaedia Britannica, 11th Edition, Volume 7, Slice 7 "Crocoite" to "Cuba" by Various

Perpendicular to the hexad axis are six dyad axes of two kinds and each perpendicular to a vertical plane of symmetry.

From Encyclopaedia Britannica, 11th Edition, Volume 7, Slice 7 "Crocoite" to "Cuba" by Various