(an atom or group of atoms with at least one unpaired electron; in the body it is usually an oxygen molecule that has lost an electron and will stabilize itself by stealing an electron from a nearby molecule) free radical; radical; radicals
(a person who has radical ideas or opinions) radical; radicals
((mathematics) a quantity expressed as the root of another quantity) radical; radicals
(a character conveying the lexical meaning of a logogram) radical; radicals