1. stupid mistake; to make a stupid mistake; stumble; say clumsily اشتباه احمقانه ، مرتکب اشتباه احمقانه ای شدن ، تلوتلو خوردن ، با دستپاچگی گفتن a. The exhausted boy blundered through the woods. b. Sert's awkward apology could not make up for his serious blunder. c. The general's blunder forced his army to a rapid retreat.