Radical meaning : (historical: 19th-century Britain) A member of the most progressive wing of the Liberal Party; someone favouring social reform (but generally stopping short of socialism). (historical: early 20th-century France) A member of an influential, centrist political party favouring moderate social reform, a republican constitution, and secular politics. A person with radical opinions. A root (of a number or quantity). In logographic writing systems such as the Chinese writing system, the portion of a character (if any) that provides an indication of its meaning, as opposed to phonetic. In Semitic languages, any one of the set of consonants (typically three) that make up a root. A group of atoms, joined by covalent bonds, that take part in reactions as a single unit. A free radical. (commutative algebra, of an ideal) Given an ideal I in a commutative ring R, another ideal, denoted Rad(I) or \sqrt{I}, such that an element x ∈ R is in Rad(I) if, for some positive integer n, xn ∈ I; equivalently, the intersection of all prime ideals containing I. (of a ring) Given a ring R, an ideal containing elements of R that share a property considered, in some sense, "not good". (of a module) The intersection of maximal submodules of a given module. The product of the distinct prime factors of a given positive integer. Favoring fundamental change, or change at the root cause of a matter. Pertaining to a root (of a plant). Pertaining to the basic or intrinsic nature of something. Thoroughgoing; far-reaching. Of or pertaining to the root of a word. (of a sound) Produced using the root of the tongue. Involving free radicals. Relating to a radix or mathematical root. (1980s & 1990s) Excellent; awesome.