Gal"le*ass (?; 135), n. [F. galéasse, galéace; cf. It. galeazza, Sp. galeaza; LL. galea a galley. See Galley.] (Naut.) A large galley, having some features of the galleon, as broadside guns; esp., such a vessel used by the southern nations of Europe in the 16th and 17th centuries. See Galleon, and Galley. [Written variously galeas, gallias, etc.]

&fist; "The galleasses . . . were a third larger than the ordinary galley, and rowed each by three hundred galley slaves. They consisted of an enormous towering structure at the stern, a castellated structure almost equally massive in front, with seats for the rowers amidships." Motley.