From Longman Dictionary of Contemporary Englishduncedunce /dʌns/ noun [countable] old-fashioned SESsomeone who is slow at learning things the dunce of the class
Examples from the Corpus
dunce• But women could be dunces too, in McCarthy's eyes.• And this, for golfing dunces, is one of the joys.• But because they looked like such retarded dunces, and women saw right through them.• He was still the school dunce.• My flaky judgments were modest by comparison-but numerous enough to keep me hopeful of regaining the dunce cap this year.• It shows just what dunces the Tories are when it comes to education.Origin dunce (1500-1600) John Duns Scotus (1266?-1308), Scottish religious thinker