3. (Integral Calculus) The integral used in obtaining the area bounded
by a curve; hence, the definite integral of the product of any function
of one variable into the differential of that variable.
4. (Astron.) The position of one heavenly body in respect to another
when distant from it 90∞, or a quarter of a circle, as the moon when at
an equal distance from the points of conjunction and opposition.
Quadrature of the moon (Astron.), the position of the moon when one
half of the disk is illuminated. -- Quadrature of an orbit (Astron.), a
point in an orbit which is at either extremity of the latus rectum
drawn through the empty focus of the orbit.
Quad"rel (?), n. [It. quadrello, LL. quadrellus, fr. L. quadrus square.
See Quadrate, and cf. Quarrel an arrow.] 1. A square piece of turf or
peat. [Prov. Eng.]