Flounder \Floun"der\, v. i. [imp. & p. p. {Floundered}; p. pr. & vb. n. {Floundering}.] [Cf. D. flodderen to flap, splash through mire, E. flounce, v.i., and flounder the fish.] To fling the limbs and body, as in making efforts to move; to struggle, as a horse in the mire, or as a fish on land; to roll, toss, and tumble; to flounce. They have floundered on from blunder to blunder. --Sir W. Hamilton.