(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.

An essential or indispensable element, condition, or ingredient.

Involving four elements.

A serving of four shots of espresso. / (chess) A kind of round-robin tournament between four players, where each participant plays every other participant once.

Having four shots of espresso.

(informal) A quadrangle (quadrangular courtyard). / (informal) A quadruplet (infant). / (informal, computer graphics) A quadrilateral. / (informal) The quadriceps muscle.

(poker slang) Of or relating to quads.

(transitive)

A quad bike (from quadricycle) / Abbreviation of quadrillion BTU. (10¹⁵ BTU)