From Longman Dictionary of Contemporary Englishhowlerhowl‧er /ˈhaʊlə $ -ər/ noun [countable] informalMISTAKE a stupid mistake that makes people laugh SYN blunder
Examples from the Corpus
howler• Know any good jokes, seen any howlers in print?• We wonder what attainment level of today's national curriculum one needs to reach before spotting that these are howlers.• Reading them saved Theobald from the editorial howlers Pope committed.• But in theology we commit enormous howlers.• He read out a selection of howlers from students' exam answers.• One of the most important is using information about the type of data stored in order to to prevent howlers.• Crossley's howler left Forest rooted to the foot of the Premier League, four points behind second-from-bottom Wimbledon. 