n. A whirl of fluid.n. Any whirling or gyratory motion; also, a whirlpool.n. In the Cartesian philosophy, a collection of material particles, forming a fluid or ether, endowed with a rapid rotatory motion about an axis, and filling all space, by which Descartes accounted for the motions of the universe. This theory attracted much attention at one time, but is now entirely discredited.n. [capitalized] [NL.] In zoology, the typical genus of Vorticidæ, containing such species as V. viridis