[n] (linguistics) the form of a word after all affixes are removed; "thematic vowels are part of the stem"
[n] a sign placed in front of an expression to denote that a root is to be extracted
[n] a character conveying the lexical meaning of a logogram
[n] a person who has radical ideas or opinions
[n] (chemistry) two or more atoms bound together as a single unit and forming part of a molecule
[n] 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"
[adj] (botany) 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"; "radical leaves"
[adj] (used of opinions and actions) far beyond the norm; "extremist political views"; "radical opinions on education"; "an ultra conservative"
[adj] markedly new or introducing radical change; "a revolutionary discovery"; "radical political views"
[adj] arising from or going to the root; "a radical flaw in the plan"
[adj] (linguistics) of or relating to or constituting a linguistic root; "a radical verb form"
basal, base, basic, chemical group, extremist, free radical, group, immoderate, new, radical sign, revolutionary, root, root, root word, stem, theme, ultra