Defn: A ray, or outer floret, of the capitulum of such plants as the sunflower and the daisy. See Ray, 2.
4. pl. (Zoöl.) (a) The barbs of a perfect. (b) Radiating organs, or color-markings, of the radiates.
5. The movable limb of a sextant or other angular instrument. Knight. Radius bar (Math.), a bar pivoted at one end, about which it swings, and having its other end attached to a piece which it causes to move in a circular arc. — Radius of curvature. See under Curvature.
RADIUS VECTOR
Ra"di*us vec"tor.
1. (Math.)
Defn: A straight line (or the length of such line) connecting any point, as of a curve, with a fixed point, or pole, round which the straight line turns, and to which it serves to refer the successive points of a curve, in a system of polar coördinates. See Coördinate, n.
2. (Astron.)
Defn: An ideal straight line joining the center of an attracting body with that of a body describing an orbit around it, as a line joining the sun and a planet or comet, or a planet and its satellite.
RADIX
Ra"dix, n.; pl. Radices, E. Radixes. Etym: [L. radix, -icis, root.
See Radish.]
1. (Philol.)