RADIATIVE
Ra"di*a*tive, a.
Defn: Capable of radiating; acting by radiation. Tyndall.
RADIATOR
Ra"di*a`tor, n.
Defn: That which radiates or emits rays, whether of light or heat; especially, that part of a heating apparatus from which the heat is radiated or diffused; as, a stream radiator.
RADICAL Rad"i*cal, a. Etym: [F., fr. L. radicalis having roots, fr. radix, - icis, a root. See Radix.]
1. Of or pertaining to the root; proceeding directly from the root.
2. Hence: Of or pertaining to the root or origin; reaching to the center, to the foundation to the ultimate sources to the principles, or the like: original; fundamental; thorough-going; unsparing; extreme; as, radical evils; radical reform; a radical party. The most determined exertions of that authority, against them, only showed their radical independence. Burke.
3. (Bot.) (a) Belonging to, or proceeding from, the root of a plant; as, radical tubers or hairs. (b) Proceeding from a rootlike stem, or one which does not rise above the ground; as, the radical leaves of the dandelion and the sidesaddle flower.
4. (Philol.)
Defn: Relating, or belonging, to the root, or ultimate source of derivation; as, a radical verbal form.