SUBDUPLICATE

Etymology

Adjective

subduplicate (not comparable)

(mathematics) Expressed by the square root; said of ratios.

Source: Wiktionary

Sub*du"pli*cate, a. (Math.)

Definition: Expressed by the square root; -- said of ratios. Subduplicate ratio, the ratio of the square roots, or the square root of a ratio; thus, the subduplicate ratio of a to b is *a to *b, or *a/b.

Source: Webster’s Unabridged Dictionary 1913 Edition