c. 1300, as opposed to darker whole-grain type, from white (adj.) + bread (n.). Its popularity among middle-class America led to the slang adjectival sense of "conventional, bourgeois" (c. 1980). Old English had hwitehlaf.
whistleblower
whistler
whistling
whit
white
white bread
white elephant
white feather
white hope
white meat
white noise