Open English Wordnet
Nouns
(n)group, radical, chemical group(chemistry) two or more atoms bound together as a single unit and forming part of a molecule
(n)free radical, radicalan 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“in the body free radicals are high-energy particles that ricochet wildly and damage cells”
Adjectives
(s)revolutionary, radicalmarkedly new or introducing radical change“a revolutionary discovery”, “radical political views”