Source : Webster's Revised Unabridged Dictionary (1913)

Promontory \Prom"on*to*ry\, n.; pl. {Promontories}. [ L.
   promonturium, promunturium; pro before + mons, montis,
   mountain: cf. F. promontoire. See {Mount}, n.]
   1. (Phys. Geog.) A high point of land or rock projecting into
      the sea beyond the line of coast; a headland; a high cape.

            Like one that stands upon a promontory. --Shak.

   2. (Anat.) A projecting part. Especially:
      (a) The projecting angle of the ventral side of the sacrum
          where it joins the last lumbar vertebra.
      (b) A prominence on the inner wall of the tympanum of the
          ear.