radical

/ˈra-di-kəl/

Middle English, from Late Latin radicalis, from Latin radic-, radix root

adjective

  1. of, relating to, or proceeding from a root: such as

  2. of or growing from the root of a plant

  3. growing from the base of a stem, from a rootlike stem, or from a stem that does not rise above the ground

noun

  1. a root part

  2. a basic principle : foundation

  3. root

noun

  1. a fashionable practice among socially prominent people of associating with radicals or members of minority groups