daft

The word "daft" has undergone a significant semantic shift from its original meaning. In Old English, it described someone who was gentle, meek, or well-mannered. By the Middle English period, the sense had softened to mean "stupid" or "foolish," likely because such mildness was misinterpreted as a lack of sharpness or spirit. This pejorative evolution continued, and in modern British English, it firmly denotes silliness or mild insanity, completely shedding its original positive connotations of suitability and gentleness.

The word is a simplex form. It is a loanword from Old English gedæfte, meaning "mild, gentle, meek," which is related to gedafen ("fitting, suitable"). Its ultimate origin is Proto-Germanic.