Po"lack (?), n. A Polander. Shak.
Po*la"cre (?), n. Same as Polacca, 1.
Po"land*er (?), n. A native or inhabitant of Poland; a Pole.
Po"lar (?), a. [Cf. F. polaire. See Pole of the earth.] 1. Of or
pertaining to one of the poles of the earth, or of a sphere; situated
near, or proceeding from, one of the poles; as, polar regions; polar
seas; polar winds.
2. Of or pertaining to the magnetic pole, or to the point to which the
magnetic needle is directed.
3. (Geom.) Pertaining to, reckoned from, or having a common radiating
point; as, polar coˆrdinates.
Polar axis, that axis of an astronomical instrument, as an equatorial,
which is parallel to the earths axis. -- Polar bear (Zoˆl.), a large
bear (Ursus, or Thalarctos, maritimus) inhabiting the arctic regions.
It sometimes measures nearly nine feet in length and weighs 1,600
pounds. It is partially amphibious, very powerful, and the most
carnivorous of all the bears. The fur is white, tinged with yellow.
Called also White bear. See Bear. -- Polar body, cell, or globule
(Biol.), a minute cell which separates by karyokinesis from the ovum
during its maturation. In the maturation of ordinary ova two polar
bodies are formed, but in parthogenetic ova only one. The first polar
body formed is usually larger than the second one, and often divides
into two after its separation from the ovum. Each of the polar bodies
removes maternal chromatin from the ovum to make room for the chromatin
of the fertilizing spermatozoˆn; but their functions are not fully
understood. -- Polar circles (Astron. & Geog.), two circles, each at a
distance from a pole of the earth equal to the obliquity of the
ecliptic, or about 23∞ 28′, the northern called the arctic
circle, and the southern the antarctic circle. -- Polar clock, a tube,
containing a polarizing apparatus, turning on an axis parallel to that
of the earth, and indicating the hour of the day on an hour circle, by
being turned toward the plane of maximum polarization of the light of
the sky, which is always 90∞ from the sun. -- Polar coˆrdinates. See
under 3d Coˆrdinate. -- Polar dial, a dial whose plane is parallel to a
great circle passing through the poles of the earth. Math. Dict. --
Polar distance, the angular distance of any point on a sphere from one
of its poles, particularly of a heavenly body from the north pole of
the heavens. -- Polar equation of a line or surface, an equation which
expresses the relation between the polar coˆrdinates of every point of
the line or surface. -- Polar forces (Physics), forces that are
developed and act in pairs, with opposite tendencies or properties in
the two elements, as magnetism, electricity, etc. -- Polar hare
(Zoˆl.), a large hare of Arctic America (Lepus arcticus), which turns
pure white in winter. It is probably a variety of the common European
hare (L. timidus). -- Polar lights, the aurora borealis or australis.
-- Polar, or Polaric, opposition or contrast (Logic), an opposition or
contrast made by the existence of two opposite conceptions which are
the extremes in a species, as white and black in colors; hence, as
great an opposition or contrast as possible. -- Polar projection. See
under Projection. -- Polar spherical triangle (Spherics), a spherical
triangle whose three angular points are poles of the sides of a given
triangle. See 4th Pole, 2. -- Polar whale (Zoˆl.), the right whale, or
bowhead. See Whale.
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Po"lar (?), n. (Conic Sections) The right line drawn through the two
points of contact of the two tangents drawn from a given point to a
given conic section. The given point is called the pole of the line. If
the given point lies within the curve so that the two tangents become
imaginary, there is still a real polar line which does not meet the
curve, but which possesses other properties of the polar. Thus the
focus and directrix are pole and polar. There are also poles and polar
curves to curves of higher degree than the second, and poles and polar
planes to surfaces of the second degree.
Pol"ar*chy (?), n. See Polyarchy.