Radicalia

Atlas

Radical 1. Referring to or belonging to the essence, the most intimate nature of a real or ideal entity; representing its primary, constitutive element; intrinsic, fundamental, substantial. 2. In Medieval physiology, designating the humours and moistures that were thought to constitute the intimate nature of all organisms and substances and which, in correct balance with natural heat, made life itself possible. 3. Indispensable element to the performing of any activity. That which is the wider, original cause.

4. Acting in depth; concerning an issue beginning with its essential principles; entirely modifying a state of aairs; complete, total. 5. A person taking to the extreme or embracing in the most rigorous manner the fundamental principles of a doctrine, science, art, or religious faith.

Also: a concrete and vigorous innovator; renewing and profoundly transforming ideological and scientific stances.

6. Of, belonging or referring to the root of a plant; constituting a root.

(Salvatore Battaglia, Grande dizionario della lingua italiana, Torino, Unione tipografico-editrice torinese, 1990; vol. XV)