bloomer
From Longman Dictionary of Contemporary Englishbloomerbloom‧er /ˈbluːmə $ -ər/ noun 1 → bloomers2 [countable]MISTAKE British English old-fashioned an embarrassing mistake that you make in front of other people – used humorously SYN blooper American EnglishExamples from the Corpusbloomer• The first thought that came to me was that I hadn't got my clean bloomers on.• A bee in her butt, a burr in her bloomers.• Over the course of the year, Farnham learned how to shingle a roof, wear bloomers, and repair a fence.