D defs.my
Entry 3 senses Webster, 1913

Watermark

/wôt'-ẽrm-ärkˌ/ · Wa·ter·mark · IPA /ˈwɔːtəmɑːk/
01 n. A mark indicating the height to which water has risen, or at which it has stood; the usual limit of high or low water.
  1. 1.
    A mark indicating the height to which water has risen, or at which it has stood; the usual limit of high or low water.
  2. 2.
    A letter, device, or the like, wrought into paper during the process of manufacture.
  3. 3.
    See Water line, 2.(Naut.) [R.] See: Water line