daft (adj.) Look up daft at Dictionary.com
Old English gedæfte "gentle, becoming," from Proto-Germanic *gadaftjaz (cognates: Old English daeftan "to put in order, arrange," gedafen "suitable;" Gothic gadaban "to be fit"), from PIE *dhabh- "to fit together." Sense progression from "mild" (c.1200) to "dull" (c.1300) to "foolish" (mid-15c.) to "crazy" (1530s) probably was influenced by analogy with daffe "halfwit."