Ra"dix (rā"dĭks), n.; pl. L. Radices (răd"ĭ*sēz), E. Radixes (rā"dĭks*ĕz). [L. radix, -icis, root. See Radish.] 1. (Philol.) A primitive word, from which spring other words; a radical; a root; an etymon.

2. (Math.) (a) A number or quantity which is arbitrarily made the fundamental number of any system; a base. Thus, 10 is the radix, or base, of the common system of logarithms, and also of the decimal system of numeration. (b) (Alg.) A finite expression, from which a series is derived. [R.] Hutton.

3. (Bot.) The root of a plant.