'Radicle' definitions:

Definition of 'radicle'

noun

(anatomy) a small structure resembling a rootlet (such as a fibril of a nerve)

From: GCIDE

Radicle \Rad"i*cle\ (r[a^]d"[i^]*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. [1913 Webster]

From: GCIDE

Caulicle \Cau"li*cle\, n. (Bot.) A short caulis or stem, esp. the rudimentary stem seen in the embryo of a seed; -- otherwise called a radicle. [1913 Webster]