polar

from The American Heritage® Dictionary of the English Language, 5th Edition.

• adjective Of or relating to a pole.
• adjective Measured from or referred to a pole.
• adjective Relating to, connected with, or located near the North Pole or South Pole.
• adjective Passing over a planet's north and south poles.
• adjective Traveling in an orbit that passes over a planet's north and south poles.
• adjective Serving as a guide, as a polestar or a pole of the earth.
• adjective Occupying or characterized by opposite extremes.
• adjective Central or pivotal.
• adjective Chemistry Relating to or characterized by a dipole.
• adjective Ionizing when dissolved or fused.

from The Century Dictionary.

• Having opposite properties at its two ends.
• noun A great circle two of whose points are each a quadrant from a given point: it is the polar of the given point.
• noun Given a trihedral; to each face from the vertex erect a perpendicular ray on the same side as the third edge; the trihedral they form is the polar of the given one.
• Of or pertaining to a pole or the poles of a sphere.
• Proceeding, issuing from, or found in the regions near the poles of the earth or of the heavens: as, the polar ocean; a polar bear.
• Pertaining to a magnetic pole or poles; pertaining to the points of a body at which its attractive or repulsive energy is concentrated.
• In anatomy, having poles in any way distinguished, as a cell: said especially of ovum-cells and nerve-cells.
• In higher geom., reciprocal to a pole; of the nature of a polar. See II.
• noun A plane curve whose point-equation is derived from that of another plane curve (with respect to which it is said to be a polar) by operating one or more times (according as it is first, second, etc., polar) with the symbol x′ . d/ d x + y'. d/ d y + z'. d/ d z, where x', y', z' are the trilinear coördinates of a fixed point (of which the curve is said to be a polar).

from the GNU version of the Collaborative International Dictionary of English.

• noun (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.
• adjective Of or pertaining to one of the poles of the earth, or of a sphere; situated near, or proceeding from, one of the poles
• adjective Of or pertaining to the magnetic pole, or to the point to which the magnetic needle is directed.
• adjective (Geom.) Pertaining to, reckoned from, or having a common radiating point.
• adjective that axis of an astronomical instrument, as an equatorial, which is parallel to the earths axis.
• adjective (Zoöl.) a large bear (Ursus maritimus syn. 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.
• adjective (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 spermatozoön; but their functions are not fully understood.
• adjective (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.
• adjective 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.
• adjective See under 3d Coördinate.
• adjective a dial whose plane is parallel to a great circle passing through the poles of the earth.
• adjective 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.
• adjective an equation which expresses the relation between the polar coördinates of every point of the line or surface.
• adjective (Physics) forces that are developed and act in pairs, with opposite tendencies or properties in the two elements, as magnetism, electricity, etc.
• adjective (Zoöl.) a large hare of Arctic America (Lepus arcticus), which turns pure white in winter. It is probably a variety of the common European hare (Lepus timidus).
• adjective the aurora borealis or australis.
• adjective (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.
• adjective See under Projection.
• adjective (Spherics) a spherical triangle whose three angular points are poles of the sides of a given triangle. See 4th Pole, 2.
• adjective (Zoöl.) the right whale, or bowhead. See Whale.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• adjective of, relating to, measured from, or referred to a geographic pole (the North Pole or South Pole)
• adjective of an orbit that passes over, or near, one of these poles