Something in the shape of a circle or ring, such as a Roman circus.
A curved depression in a mountainside with steep walls, forming the end of a valley.
A whirlwind, whirlpool, or similarly moving matter in the form of a spiral or column.
Anything that involves constant violent or chaotic activity around some centre.
Anything that inevitably draws surrounding things into its current.
A supposed collection of particles of very subtle matter, endowed with a rapid rotary motion around an axis which was also the axis of a sun or planet; part of a Cartesian theory accounting for the formation of the universe, and the movements of the bodies composing it.
Any of numerous species of small Turbellaria belonging to Vortex and allied genera.
To mix using a vortex mixer