radix

A root or point of origin.

The base of a system of numbers, such as 2 in the binary system and 10 in the decimal system.

In astrology, the original figure of birth, the source of all judgments and predictions.

The root of a plant: used chiefly with reference to the roots of medicinal plants or preparations from them.

Hence The primary source or origin; that from which anything springs, or in which it originates.