Vocabulary : Equant to Equerry

Equant : A circle around whose circumference a planet or the center of ann epicycle was conceived to move uniformly; -- called also eccentric equator.
Equate : To make equal; to reduce to an average; to make such an allowance or correction in as will reduce to a common standard of comparison; to reduce to mean time or motion; as, to equate payments; to equate lines of railroad for grades or curves; equated distances.
Equated : of Equate
Equating : of Equate
Equation : A making equal; equal division; equality; equilibrium. ;; An expression of the condition of equality between two algebraic quantities or sets of quantities, the sign = being placed between them; as, a binomial equation; a quadratic equation; an algebraic equation; a transcendental equation; an exponential equation; a logarithmic equation; a differential equation, etc. ;; A quantity to be applied in computing the mean place or other element of a celestial body; that is, any one of the several quantities to be added to, or taken from, its position as calculated on the hypothesis of a mean uniform motion, in order to find its true position as resulting from its actual and unequal motion.

Equator : The imaginary great circle on the earth's surface, everywhere equally distant from the two poles, and dividing the earth's surface into two hemispheres. ;; The great circle of the celestial sphere, coincident with the plane of the earth's equator; -- so called because when the sun is in it, the days and nights are of equal length; hence called also the equinoctial, and on maps, globes, etc., the equinoctial line.
Equatorial : Of or pertaining to the equator; as, equatorial climates; also, pertaining to an equatorial instrument. ;; An instrument consisting of a telescope so mounted as to have two axes of motion at right angles to each other, one of them parallel to the axis of the earth, and each carrying a graduated circle, the one for measuring declination, and the other right ascension, or the hour angle, so that the telescope may be directed, even in the daytime, to any star or other object whose right ascension and declination are known. The motion in right ascension is sometimes communicated by clockwork, so as to keep the object constantly in the field of the telescope. Called also an equatorial telescope.
Equatorially : So as to have motion or direction parallel to the equator.
Equerries : of Equerry
Equerry : A large stable or lodge for horses. ;; An officer of princes or nobles, charged with the care of their horses.