RADICAL

I. adjective see: root Date: 14th century of, relating to, or proceeding from a root: as, a. of or growing from the root of a plant , growing from the base of a stem, from a rootlike stem, or from a stem that does not rise above the ground , of, relating to, or constituting a linguistic root, of or relating to a mathematical root, designed to remove the root of a disease or all diseased and potentially diseased tissue , of or relating to the origin ; fundamental , 3. marked by a considerable departure from the usual or traditional ; extreme , tending or disposed to make extreme changes in existing views, habits, conditions, or institutions, of, relating to, or constituting a political group associated with views, practices, and policies of extreme change, advocating extreme measures to retain or restore a political state of affairs , excellent , cool , ~ness noun II. noun Date: 1641 1. a root part, a basic principle ; foundation , 2. root 6, a sound or letter belonging to a ~, one who is ~, free ~ , 5. a mathematical expression indicating a root by means of a ~ sign, ~ sign