v. 1 stumble, flounder I had somehow blundered into a meeting of the local crime syndicate She blundered upon the truth when she saw them together.
n. 2 mistake, error, gaffe, faux pas, slip, slip-up, howler, Colloq boo-boo, screw-up, fluff, boner, US goof, goof-up I made a stupid blunder in telling him about the plans