3. (Crystallog.) Designating, or belonging to, a certain system of
crystallization; dimetric. See Tetragonal system, under
Crystallization.
||Tet`ra*gram"ma*ton (?), n. [NL., fr. Gr. &?;; te`tra- (see Tetra-) +
||&?; a letter.] The mystic number four, which was often symbolized to
||represent the Deity, whose name was expressed by four letters among
||some ancient nations; as, the Hebrew JeHoVaH, Greek qeo`s, Latin
||deus, etc.
||
||Tet`ra*gyn"i*a (?), n. pl. [NL., fr. Gr. te`tra- (see Tetra-) + gynh`
||a woman, female.] (Bot.) A Linnæan order of plants having four styles.
||
{ Tet`ra*gyn"i*an (?), Te*trag"y*nous (?), } a. (Bot.) Belonging to the
order Tetragynia; having four styles.
Tet`ra*he"dral (?), a. [See Tetrahedron.] 1. Having, or composed of,
four sides.
2. (Crystallog.) (a) Having the form of the regular tetrahedron. (b)
Pertaining or related to a tetrahedron, or to the system of hemihedral
forms to which the tetrahedron belongs.
Tetrahedral angle (Geom.), a solid angle bounded or inclosed by four
plane angles.
Tet`ra*he"dral*ly, adv. In a tetrahedral manner.
Tet`ra*he"drite (?), n. [So called because the crystals of the species
are commonly tetrahedrons.] (Min.) A sulphide of antimony and copper,
with small quantities of other metals. It is a very common ore of
copper, and some varieties yield a considerable presentage of silver.
Called also gray copper ore, fahlore, and panabase.
Tet`ra*he"dron (?), n. [Tetra- + Gr. &?; seat, base, fr. &?; to sit.]
(Geom.) A solid figure inclosed or bounded by four triangles.
In crystallography, the regular tetrahedron is regarded as the
hemihedral form of the regular octahedron.
Regular tetrahedron (Geom.), a solid bounded by four equal equilateral
triangles; one of the five regular solids.
Tet`ra*hex`a*he"dral (?), a. (Crystallog.) Pertaining to a
tetrahexahedron.
Tet`ra*hex`a*he"dron (?), n. [Tetra- + hexahedron.] (Crystallog.) A
solid in the isometric system, bounded by twenty-four equal triangular
faces, four corresponding to each face of the cube.
Tet`ra*kis*hex`a*he"dron (?), n. [Gr. &?; four times + E. hexahedron.]
(Crystallog.) A tetrahexahedron.
Tet"ra*ko*sane` (?), n. [Tetra- + Gr. &?; twenty.] (Chem.) A
hydrocarbon, C24H50, resembling paraffin, and like it belonging to the
marsh-gas series; — so called from having twenty-four atoms of carbon
in the molecule.
Te*tral"o*gy (?), n. [Gr. &?;; te`tra- (see Tetra-) + &?; a speech,
discourse: cf. F. tétralogie.] (Gr. Drama) A group or series of four
dramatic pieces, three tragedies and one satyric, or comic, piece (or
sometimes four tragedies), represented consequently on the Attic stage
at the Dionysiac festival.
A group or series of three tragedies, exhibited together without a
fourth piese, was called a trilogy.
||Te*tram"e*ra (?), n. pl. [NL. See Tetramerous.] (Zoöl.) A division of
||Coleoptera having, apparently, only four tarsal joints, one joint
||being rudimentary.
||
Te*tram"er*ous (?), a. [Tetra- + Gr. &?; part.] 1. (Bot.) Having the
parts arranged in sets of four; as, a tetramerous flower.
2. (Zoöl.) Having four joints in each of the tarsi; — said of certain
insects.
Te*tram"e*ter (?), n. [L. tetrametrus, Gr. &?;; te`tra- (see Tetra-) +
&?; a measure: cf. F. tétramètre.] (GR. & Latin Pros.) A verse or line
consisting of four measures, that is, in iambic, trochaic, and
anapestic verse, of eight feet; in other kinds of verse, of four feet.
Tet`ra*meth"yl*ene (?), n. [Tetra- + methylene.] (Chem.) (a) A
hypothetical hydrocarbon, C4H8, analogous to trimethylene, and regarded
as the base of well-known series or derivatives. (b) Sometimes, an
isomeric radical used to designate certain compounds which are really
related to butylene.
Tet"ra*morph (?), n. [Tetra- + Gr. &?; form, figure: cf. Gr. &?;
fourfold.] (Christian Art) The union of the four attributes of the
Evangelists in one figure, which is represented as winged, and standing
on winged fiery wheels, the wings being covered with eyes. The
representations of it are evidently suggested by the vision of Ezekiel
(ch. i.)
||Te*tran"dri*a (?), n. pl. [NL., from Gr. te`tra- (see Tetra-) + &?;,
||&?;, a man, male.] (Bot.) A Linnæan class of plants having four
||stamens.
||
{ Te*tran"dri*an (?), Te*tran"drous (?), } a. (Bot.) Belonging to the
class Tetrandria.
<! p. 1492 !>
Te*tra"o*nid (?), n. [L. tetrao a heath cock, grouse, Gr. &?;: cf. F.
tétraonide.] (Zoöl.) A bird belonging to the tribe of which the genus
Tetrao is the type, as the grouse, partridge, quail, and the like. Used
also adjectively.
Tet`ra*pet"al*ous (?), a. [Tetra- + petal.] (Bot.) Containing four
distinct petals, or flower leaves; as, a tetrapetalous corolla.
{ Tet`ra*phar"ma*com (?), Tet`ra*phar"ma*cum (?) }, n. [NL.
tetrapharmacon, L. tetrapharmacum, Gr. &?;; te`tra- (see Tetra-) + &?;
a drug.] (Med.) A combination of wax, resin, lard, and pitch, composing
an ointment. Brande & C.