Defn: An atom whose valence is six, and which can be theoretically combined with, substituted for, or replaced by, six monad atoms or radicals; as, sulphur is a hexad in sulphuric acid. Also used as an adjective.

HEXADACTYLOUS
Hex`a*dac"tyl*ous, a. Etym: [Gr. hexadactyle.] (Zoöl.)

Defn: Having six fingers or toes.

HEXADE
Hex"ade, n. Etym: [See Hexad.]

Defn: A series of six numbers.

HEXADECANE
Hex"a*dec`ane, n. (Chem.)

Defn: See Hecdecane.

HEXAGON
Hex"a*gon, n. Etym: [L. hexagonum, Gr. six) + (Geom.)

Defn: A plane figure of six angles. Regular hexagon, a hexagon in which the angles are all equal, and the sides are also all equal.

HEXAGONAL
Hex*ag"o*nal, a. Etym: [Cf. F. hexagonal.]