**The Collaborative International Dictionary of English v.0.48:**

Conjugate \Con"ju*gate\, a. [L. conjugatus, p. p. or conjugare
to unite; con- + jugare to join, yoke, marry, jugum yoke;
akin to jungere to join. See Join.]
1. United in pairs; yoked together; coupled.
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2. (Bot.) In single pairs; coupled.
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3. (Chem.) Containing two or more compounds or radicals
supposed to act the part of a single one. [R.]
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4. (Gram.) Agreeing in derivation and radical signification;
-- said of words.
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5. (Math.) Presenting themselves simultaneously and having
reciprocal properties; -- frequently used in pure and
applied mathematics with reference to two quantities,
points, lines, axes, curves, etc.
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Conjugate axis of a hyperbola (Math.), the line through the
center of the curve, perpendicular to the line through the
two foci.
Conjugate diameters (Conic Sections), two diameters of an
ellipse or hyperbola such that each bisects all chords
drawn parallel to the other.
Conjugate focus (Opt.) See under Focus.
Conjugate mirrors (Optics), two mirrors so placed that rays
from the focus of one are received at the focus of the
other, especially two concave mirrors so placed that rays
proceeding from the principal focus of one and reflected
in a parallel beam are received upon the other and brought
to the principal focus.
Conjugate point (Geom.), an acnode. See Acnode, and
Double point.
Self-conjugate triangle (Conic Sections), a triangle each
of whose vertices is the pole of the opposite side with
reference to a conic.
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