Part 14

2. (Bot.) The disposition of the roots of a plant.

Rad"i*cel (rd"*sl), n. [Dim. of radix.] (Bot.) A small branch of a root; a rootlet.

Ra*dic`i*flo"rous (r*ds`*fl"rs), a. [L. radix, -icis, root + flos, floris, a flower.] (Bot.) Rhizanthous.

Ra*dic"i*form (r*ds"*fôm), a. (Bot.) Having the nature or appearance of a radix or root.

Rad"i*cle (rd"*k'l), n. [L. radicula, dim. of radix, -icis, root: cf. F. radicule. See Radix.] (Bot.) (a) The rudimentary stem of a plant which supports the cotyledons in the seed, and from which the root is developed downward; the stem of the embryo; the caulicle. (b) A rootlet; a radicel.

Ra*dic"u*lar (r*dk"*lr), a. Of or pertaining to roots, or the root of a plant.

Rad"i*cule (rd"*kl), n. (Bot.) A radicle.

Ra*dic"u*lose` (r*dk"*ls`), a. (Bot.) Producing numerous radicles, or rootlets.

Ra"di*i (r"d*), n., pl. of Radius.

Ra"di*o- (r"d*-). A combining form indicating connection with, or relation to, a radius or ray; specifically (Anat.), with the radius of the forearm; as, radio-ulnar, radio- muscular, radio-carpal.

||Ra`di*o-flag`el*la"ta (- flj`l*l"t), n. pl. [NL. See Radiate, and ||Flagellata.] (Zoöl.) A group of Protozoa having both flagella and ||pseudopodia.

Ra"di*o*graph (r"d**grf), n. [Radio- + -graph.] (Phys.) A picture produced by the Röntgen rays upon a sensitive surface, photographic or fluorescent, especially a picture of opaque objects traversed by the rays.

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||Ra`di*o*la"ri*a (r`d**l"r*), n. pl. [NL. See Radioli.] (Zoöl.) Order ||of rhizopods, usually having a siliceous skeleton, or shell, and ||sometimes radiating spicules. The pseudopodia project from the body ||like rays. It includes the polycystines. See Polycystina.

Ra`di*o*la"ri*an (r`d**l"r*an), a. (Zoöl.) Of or pertaining to the Radiolaria. -- n. One of the Radiolaria.

||Ra*di"o*li (r*d"*l), n. pl.; sing. Radiolus (-ls). [NL., dim. of L. ||radius radius: cf. L. radiolus a feeble sunbeam.] (Zoöl.) The barbs ||of the radii of a feather; barbules.

Ra"di*o*lite (r"d**lt), n. [L. radius ray + -lite: cf. F. radiolithe.] (Paleon.) A hippurite.

Ra`di*om"e*ter (-m"*tr), n. [L. radius radius + -meter: cf. F. radiomètre.] 1. (Naut.) A forestaff.

2. (Physics) An instrument designed for measuring the mechanical effect of radiant energy.

It consists of a number of light disks, blackened on one side, placed at the ends of extended arms, supported on a pivot in an exhausted glass vessel. When exposed to rays of light or heat, the arms rotate.

Ra`di*o*mi*crom"e*ter (- *m*krm"*tr), n. [Radio- + micrometer.] (Physics) A very sensitive modification or application of the thermopile, used for indicating minute changes of radiant heat, or temperature.

Ra"di*o*phone (r"d**fn), n. [Radio- + Gr. fwnh` sound.] (Physics) An apparatus for the production of sound by the action of luminous or thermal rays. It is essentially the same as the photophone.

Ra`di*oph"o*ny (-f"*n), n. (Physics) The art or practice of using the radiophone.

Ra"di*ous (r"d*s), a. [L. radiosus.] 1. Consisting of rays, as light. [R.] Berkeley.

2. Radiating; radiant. [Obs.] G. Fletcher.

Rad"ish (rd"sh), n. [F. radis; cf. It. radice, Pr. raditz; all fr. L. radix, -icis, a root, an edible root, especially a radish, akin to E. wort. See Wort, and cf. Eradicate, Race a root, Radix.] (Bot.) The pungent fleshy root of a well-known cruciferous plant (Raphanus sativus); also, the whole plant.

Radish fly (Zoöl.), a small two- winged fly (Anthomyia raphani) whose larvæ burrow in radishes. It resembles the onion fly. -- Rat-tailed radish (Bot.), an herb (Raphanus caudatus) having a long, slender pod, which is sometimes eaten. -- Wild radish (Bot.), the jointed charlock.

Ra"di*us (r"d*s), n.; pl. L. Radii (- ); E. Radiuses (-s*z). [L., a staff, rod, spoke of a wheel, radius, ray. See Ray a divergent line.] 1. (Geom.) A right line drawn or extending from the center of a circle to the periphery; the semidiameter of a circle or sphere.