polar(redirected from polar spongioblastoma)
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1. situated at or near, coming from, or relating to either of the earth's poles or the area inside the Arctic or Antarctic Circles
2. having or relating to a pole or poles
a. (of a molecule or compound) being or having a molecule in which there is an uneven distribution of electrons and thus a permanent dipole moment
b. (of a crystal or substance) being or having a crystal that is bound by ionic bonds
polar(poh -ler) (polar system) See magnetic cataclysmic variables.
A member of a class of cataclysmic variable stars whose light displays strong circular polarization. Also known as AM Herculis star.
For a conic section, the polar of a point is the line that passes through the points of contact of the two tangents drawn to the conic from the point.
For a quadric surface, the polar of a point is the plane that passes through the curve which is the locus of the points of contact of the tangents drawn to the surface from the point.
For a quadric surface, the polar of a line is the line of intersection of the planes which are tangent to the surface at its points of intersection with the original line.