Chapter Pygobranchia to Pyrogenic of P by Webster's Dictionary (1913 Edition)

Pyocyanin
(Py`o*cy"a*nin) n. [Gr. pus + dark blue.] (Physiol. (Chem.) A blue coloring matter found in the pus from old sores, supposed to be formed through the agency of a species of bacterium

Pyogenic
(Py`o*gen"ic) a. [Gr. pus + root of to be born.] (Med.) Producing or generating pus.

Pyoid
(Py"oid) a. [Gr. pus + -- oid.] (Med.) Of or pertaining to pus; of the nature of, or like, pus.

Pyoid corpuscles (Med.), cells of a size larger than pus corpuscles, containing two or more of the latter.

Pyopneumothorax
(Py`op*neu`mo*tho"rax) n. [Gr. pus + E. pneumothorax.] (Med.) Accumulation of air, or other gas, and of pus, in the pleural cavity.

Pyot
(Py"ot) n. (Zoöl.) The magpie. See Piet.

Pyoxanthose
(Py`o*xan"those) n. [Gr. pus + yellow.] (Physiol. (Chem.) A greenish yellow crystalline coloring matter found with pyocyanin in pus.

Pyracanth
(Pyr"a*canth) n. [Gr. fire + a thorn, prickly plant.] (Bot.) The evergreen thorn a shrub native of Europe.

Pyral
(Py"ral) a. Of or pertaining to a pyre. [R.]

Pyralid
(Pyr"a*lid) n. [L. pyralis, -idis, a kind of winged insect.] (Zoöl.) Any moth of the family Pyralidæ. The species are numerous and mostly small, but some of them are very injurious, as the bee moth, meal moth, hop moth, and clover moth.

Pyramid
(Pyr"a*mid) n. [L. pyramis, -idis, fr. Gr. of Egyptian origin: cf. F. pyramide.]

1. A solid body standing on a triangular, square, or polygonal base, and terminating in a point at the top; especially, a structure or edifice of this shape.

2. (Geom.) A solid figure contained by a plane rectilineal figure as base and several triangles which have a common vertex and whose bases are sides of the base.

3. pl. (Billiards) The game of pool in which the balls are placed in the form of a triangle at spot. [Eng.]

Altitude of a pyramid (Geom.), the perpendicular distance from the vertex to the plane of the base. — Axis of a pyramid (Geom.), a straight line drawn from the vertex to the center of the base. — Earth pyramid. (Geol.) See Earth pillars, under Earth. — Right pyramid (Geom.) a pyramid whose axis is perpendicular to the base.

Pyramidal
(Py*ram`i*dal) a. [Cf. F. pyramidal.]

1. Of or pertaining to a pyramid; in the form of a a pyramid; pyramidical; as, pyramidal cleavage.

The mystic obelisks stand up
Triangular, pyramidal.

Mrs. Browning.

2. (Crystallog.) Same as Tetragonal.

Pyramidal numbers (Math.), certain series of figurate numbers expressing the number of balls or points that may be arranged in the form of pyramids. Thus 1, 4, 10, 20, 35, etc., are triangular pyramidal numbers; and 1, 5, 14, 30, 55, etc., are square pyramidal numbers.

Pyramidal
(Py*ram"i*dal) n. (Anat.) One of the carpal bones. See Cuneiform, n., 2 (b).

Pyramidally
(Py*ram"i*dal*ly), adv. Like a pyramid.