Desaturate
From The Glossary of Digital Photography
Removing the color from an image, which leaves behind a grayscale (sometimes called a black-and-white) image. Although desaturating is one way of creating a grayscale image, there are other methods that give more creative choices and can produce an image with a more pleasing appearance. A desaturate function is available in Photoshop and other image-manipulation programs. See also gray scale
