Today’s d word comes as a very belated response to a request made by Paul Thomas way back in 2013. The word up for consideration is daft, whose etymology is long, winding and, to be honest, pretty daft.
The word derives from the Old English gedaefte which originally meant ‘mild, gentle, becoming’. Tracing the origin back further, we find *gadaftjaz in Proto-Germanic which also gave rise to the related words daeftan, ‘to put in order, arrange’, and gedafen, ‘suitable’ in Old English. Going back even further, we find the root*dhabh- ‘to fit together’ in Proto-Indo-European.
Now of course, daft no longer means ‘mild, becoming’ or has any connotation of being suitably arranged, but it means something altogether different; the definition given by Oxford Dictionaries is ‘silly, foolish’. So the word has definitely become more negative, which, in linguistic terms, we call pejoration. But how has this happened?
By Middle English, around 1200, daffte meant ‘quiet and humble’. One hundred years later, it meant ‘dull’. In another 150 years, it meant ‘foolish’ and in the 1530s it even went one step further to become synonymous with ‘crazy’.
Daft first had the meaning of ‘stupid’ in reference to animals: a mild, humble animal was also considered simple. This meaning was eventually applied to people too. The progression could also have been influenced by analogy with another word, daffe, which then meant ‘half-wit’.
A surprising relative of daft is deft, which comes from the same Old English root gedaefte. The two words split sometime in the 15th century. While daft’s ‘gentle’ meaning went on to become ‘foolish’, deft developed the ‘gentle’ meaning into ‘skillful’ and ‘subtle’. So perhaps being called daft is not so bad after all.