(figuratively, slang, hyperbolic) Any very large number, exceeding normal description.

square-shaped / (mathematics) of a polynomial, involving the second power (square) of a variable but no higher powers, as ax²+bx+c. / (mathematics) of an equation, of the form ax²+bx+c=0.

(mathematics) A quadratic polynomial, function or equation.

(geometry) A quadrilateral whose vertices all intersect a single circle.

(dated) A person of three-fourths Caucasian descent and one fourth African descent. / (Australia, dated) A person of three-quarters Caucasian descent and one quarter Aboriginal descent.

(dated) Having three-fourths Caucasian descent and one-fourth African descent.

(Christianity) Synonym of Lent. / (Christianity) Synonym of Quadragesima Sunday: the first Sunday in Lent.

(basketball) The achievement of a two-digit number of any four of points scored, assists, rebounds, blocks, or steals in a single game.

(geometry) A geometric shape with four angles and four straight sides; a four-sided polygon. / A courtyard which is quadrangular. / The buildings forming the border of such a courtyard.

(education, historical) The higher division of the seven liberal arts in the Middle Ages, composed of geometry, astronomy, arithmetic, and music.