A rootlet or structure resembling one, as the radicle of a vein, a minute veinlet joining with others to form a vein, or the radicle of a nerve, a nerve fiber that joins others to form a nerve; the smallest branches of a vessel or nerve.
[L. radicula, dim. of radix, root]
Search Stedman's Medical Dictionary
Examples: glitazone, GI cocktail, etc.