| 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 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” |
| noun | a person who has radical ideas or opinions |
| noun | (mathematics) a quantity expressed as the root of another quantity |
| noun | a character conveying the lexical meaning of a logogram |
| noun | (linguistics) the form of a word after all affixes are removed “thematic vowels are part of the stem” |
| adjective | (used of opinions and actions) far beyond the norm “extremist political views” |
| adjective | markedly new or introducing radical change “a revolutionary discovery” |
| adjective | arising from or going to the root or source “a radical flaw in the plan” |
| adjective | of or relating to or constituting a linguistic root “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 “basal placentation” |
| stem | verb | remove the stem from |
| revolution | noun | a drastic and far-reaching change in ways of thinking and behaving |
| base | noun | (anatomy) the part of an organ nearest its point of attachment |