U and non-U

U means socially acceptable or correct and non-U means the opposite. They stand for ‘upper class’ and ‘non upper class’ respectively. These expressions were popularised by Nancy Mitford in an essay Noblesse Oblige published in 1956 where she listed a number of expressions classified under the headings of ‘U’ and ‘Non-U’. For example, words like dessert, serviette, toilet, dinner jacket, greens, are all non-U, whereas their equivalents, pudding, napkin, lavatory, dress suit and vegetables are U. Two years before Mitford’s essay, the terms U and non-U were coined by Alan S.C. Ross, Professor of Linguistics at Birmingham University but it was Mitford and her lists of U and non-U expressions that made them famous.