Sĕs'qui-ăl'ter-al or Sĕs'qui-ăl'ter-ate, a.

a. [Lat. sesquialter, once and a half, from sesqui and alter, other; Fr. sesquialtère.] One and a half of another.

Sesquialteral floret (Bot.), a large, fertile floret, accompanied with a small, abortive one.—Sesquialteral ratio (Math.), the ratio of one and a half to one; thus 9 and 6 are in a sesquialteral ratio.