blunder

Etymology

From Middle English blunder, blonder (“disturbance, strife”), from Middle English blundren, blondren (verb), which itself is partly from Middle English blondren, a frequentative form of Middle English blonden, blanden ("to mix; mix up"; corresponding to blend + -er); and partly from Middle English blundren, a frequentative form of Middle English blunden (“to stagger; stumble”), from Old Norse blunda (“to shut the eyes; doze”). Cognates include Norwegian blunda (“to shut the eyes; doze”), dialectal Swedish blundra (“to act blindly or rashly”), Danish blunde (“to blink”) or blunde (“to take a nap”). Related to English blind.

noun

1. A clumsy or embarrassing mistake.
2. (chess) A very bad move, usually caused by some tactical oversight.

verb

1. (intransitive) To make a clumsy or stupid mistake.
   to blunder in preparing a medical prescription
2. (intransitive) To move blindly or clumsily.
   I was never distinguished for address, and have often even blundered in making my bow. October 6, 1759, Oliver Goldsmith, The Bee No. 1
3. (transitive) To cause to make a mistake.
   To blunder an adversary. 1714, Humphry Ditton, A discourse concerning the resurrection of Jesus Christ
4. (transitive) To do or treat in a blundering manner; to confuse.
   He blunders and confounds all these together. 1676, Edward Stillingfleet, A Defence of the Discourse Concerning the Idolatry Practised in the Church of Rome