Source : WordNet®

picture element
     n : (computer science) the smallest discrete component of an
         image or picture on a CRT screen (usually a colored dot);
         "the greater the number of pixels per inch the greater
         the resolution" [syn: {pixel}, {pel}]

Source : Free On-Line Dictionary of Computing

picture element
     
         (pixel) The smallest resolvable rectangular area of
        an {image}, either on a screen or stored in memory.  Each
        pixel in a {monochrome} image has its own brightness, from 0
        for black to the maximum value (e.g. 255 for an eight-bit
        pixel) for white.  In a colour image, each pixel has its own
        brightness and colour, usually represented as a triple of red,
        green and blue intensities (see {RGB}).
     
        Compare {voxel}.
     
        (1998-05-08)