Source : WordNet®

zoom
     v 1: move along very quickly [syn: {zoom along}, {whizz}, {whizz
          along}]
     2: move with a low humming noise
     3: rise rapidly; "the dollar soared against the yes" [syn: {soar},
         {soar up}, {soar upwards}, {surge}]

zoom
     n 1: a rapid rise [syn: {rapid climb}, {rapid growth}]
     2: the act of rising upward into the air [syn: {soar}]

Source : Free On-Line Dictionary of Computing

zoom
     
         To show a smaller area of an {image} at a higher
        magnification ("zoom in") or a larger area at a lower
        magnification ("zoom out"), as though using a zoom lense on a
        camera.
     
        Unlike in an optical system, zooming in on a computer {image}
        does not necessarily increase the amount of detail displayed
        since this is limited by what is actually stored in the image.
        Similarly, you cannot zoom out beyond the full size of the
        image.
     
        (1997-10-24)