Synonyms for Blunder (same or very similar meaning)
WordNet sense 1 (commit a faux pas or a fault or make a serious mistake):
goof, sin, sinWordNet sense 2 (make one's way clumsily or blindly):
fumbleWordNet sense 3 (utter impulsively):
blurt, ejaculate, ejaculate, blurt out, blunder outWordNet sense 4 (an embarrassing mistake):
bloomer, blooper, botch, bungle, flub, foul-up, pratfall, boo-boo, fuckupFrom the ODE community, based on WordNetadd/edit