sesquialterate

Ses`qui*al"ter*al, Ses`qui*al"ter*ate, a. Etym: [L. sesquialter once and a half; sesqui- + alter other: cf. F. sesquialtére.] Defn: Once and a half times as great as another; having the ratio of one and a half to one. Sesquialteral ratio (Math.), the ratio of one and a half to one; thus, 9 and 6 are in a sequialteral ratio.

---