Subduple
Pronunciation : Sub"du*ple
Part of Speech : a.
Definition : Defn: Indicating one part of two; in the ratio of one to two. Subduple ratio, the ratio of 1 to 2: thus, 3:6 is a subduple ratio, as 6:3 is a duple ratio.
(Math.)
Source : Webster's Unabridged Dictionary, 1913