Bateau \Ba*teau"\, n.; pl. {Bateaux}. [F. bateau, LL. batellus, fr. battus, batus, boat, which agrees with AS. b[=a]t boat: cf. W. bad boat. See {Boat}, n.] A boat; esp. a flat-bottomed, clumsy boat used on the Canadian lakes and rivers. [Written also, but less properly, {batteau}.] [1913 Webster] {Bateau bridge}, a floating bridge supported by bateaux. [1913 Webster]