Sesquiduplicate
Pronunciation : Ses`qui*du"pli*cate
Part of Speech : a.
Etymology : [Sesqui- + duplicate.]
Definition : Defn: Twice and a half as great (as another thing); having the ratio of two and a half to one. Sesquiduplicate ratio (Math.), the ratio of two and a half to one, or one in which the greater term contains the lesser twice and a half, as that of 50 to 20.
Source : Webster's Unabridged Dictionary, 1913