Noun

(countable, anatomy) The outer layer of an internal organ or body structure, such as the kidney or the brain.

(uncountable, botany) The tissue of a stem or root that lies inward from the epidermis, but exterior to the vascular tissue.

Noun

(en-noun)

A whirlwind, whirlpool, or similarly moving matter in the form of a spiral or column.

* {{quote-magazine, date=2013-03

, author=Frank Fish, George Lauder , title=Not Just Going with the Flow , volume=101, issue=2, page=114 , magazine= citation , passage=An extreme version of vorticity is a vortex'''''. The ' vortex is a spinning, cyclonic mass of fluid, which can be observed in the rotation of water going down a drain, as well as in smoke rings, tornados and hurricanes.}}

(figuratively) Anything that involves constant violent or chaotic activity around some centre.

(figuratively) Anything that inevitably draws surrounding things into its current.

(historical) 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.

(zoology) Any of numerous species of small Turbellaria belonging to Vortex and allied genera.