1.(chemistry) two or more atoms bound together as a single unit and forming part of a molecule
2.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;
in the body free radicals are high-energy particles that ricochet wildly and damage cells
3.a person who has radical ideas or opinions
4.a character conveying the lexical meaning of a logogram
5.a sign placed in front of an expression to denote that a root is to be extracted
6.(linguistics) the form of a word after all affixes are removed;
thematic vowels are part of the stem
7.(used of opinions and actions) far beyond the norm;
extremist political views
8.markedly new or introducing radical change;
a revolutionary discovery
9.arising from or going to the root;
a radical flaw in the plan
10.of or relating to or constituting a linguistic root;
a radical verb form
11.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