swordfish /ˈsɔː(ɹ)dfɪʃ/noun 2verb 1forms 3 noun2 •A large marine fish with a long, pointed bill, Xiphias gladius.One reason, the department suggested, was that affluent New Yorkers were likely to eat expensive fish high in mercury, like swordfish and tuna. — 2008 •A sudoku technique involving possible cell locations for a digit, or pair, or triple, in uniquely three rows and three columns only. This allows for the elimination of candidates around the grid. verb1 •To fish for swordfish. formsswordfished · swordfishing · swordfishes