A film medium using gradients from black to white across a spectrum of grays.
Or hell, Webster:
1. adj. displaying only black and white tones, without color, as a picture or chart: a black-and-white photograph
2. partly black and partly white; made up of separate areas or design elements of black and white: black-and-white shoes
3. of, petaining to, or constituting a two-valued system, as of logic or morality; absolute: To those who think in black-and-white terms, a person must be either entirely good or entirely bad...
Webster's unabridged, 1996 edition
Opinion - movies filmed, conceived, directed and acted, created as an artistic whole in black-and-white should be left alone, not muddled with. I have tried turning off the color on the TV while watching the bastardized colorized versions Ted Turner had the gall to put out, and they are still not quite acceptable, the film looks like it is viewed through a guaze, it loses crispness and shadow. Howard Hawks created in black-and-white, he made visual finished artistic masterpieces (or not) - let's add some fucking vibrant colours to the Taj Mahal, eh Ted? What an asshole.