"You canker blossom!" 3 Shakespearean Insults
1596, in blatant beast, coined by Edmund Spenser in "The Faerie Queen" to describe a thousand-tongued monster representing slander; probably suggested by Latin blatire "to babble." It entered general use 1650s, as "noisy in an offensive and vulgar way;" the sense of "obvious, glaringly conspicuous" is from 1889. Related: Blatantly.