xiphioid,a.andn.Zool.|ˈzɪfɪɔɪd| [f.prec. + -oid.] a.adj. Resembling or allied to the genus Xiphias; belonging to or having the characters of the family Xiphiidæ. b.n. A xiphioid fish. 1851Mantell Petrifactions v. §1. 416 Cycloid Order... Xiphioids.1891Cent.Dict., Xiphioid, a. and n.