- academically subnormal
- of very low ability or intelligenceLogic tells us that half of any class will be above the mean, and half below it:The BBC had been offered the series and had turned it down because one of the pupils was 'academically subnormal'. (F. Muir, 1997, writing about of the television programme Please Sir)
How not to say what you mean: A dictionary of euphemisms. R. W. Holder. 2014.