noun: a sign placed in front of an expression to denote that a root is to be extracted
noun: a character conveying the lexical meaning of a logogram
noun: a person who has radical ideas or opinions
noun: (chemistry) two or more atoms bound together as a single unit and forming part of a molecule
noun: an atom or group of atoms with at least one unpaired electron; in the body it is usually an oxygen molecule than has lost an electron and will stabilize itself by stealing an electron from a nearby molecule
Example: "In the body free radicals are high-energy particles that ricochet wildly and damage cells"
noun: (linguistics) the form of a word after all affixes are removed
adjective: arising from or going to the root
Example: "A radical flaw in the plan"
adjective: of or relating to or constituting a linguistic root
Example: "A radical verb form"
adjective: especially of leaves; located at the base of a plant or stem; especially arising directly from the root or rootstock or a root-like stem
Example: "Radical leaves"
adjective: (used of opinions and actions) far beyond the norm
Example: "Radical opinions on education"
adjective: markedly new or introducing radical change