Source : Webster's Revised Unabridged Dictionary (1913)

Bank \Bank\ (b[a^][ng]k), n. [OE. banke; akin to E. bench, and
   prob. of Scand. origin.; cf. Icel. bakki. See {Bench}.]
   1. A mound, pile, or ridge of earth, raised above the
      surrounding level; hence, anything shaped like a mound or
      ridge of earth; as, a bank of clouds; a bank of snow.

            They cast up a bank against the city. --2 Sam. xx.
                                                  15.

   2. A steep acclivity, as the slope of a hill, or the side of
      a ravine.

   3. The margin of a watercourse; the rising ground bordering a
      lake, river, or sea, or forming the edge of a cutting, or
      other hollow.

            Tiber trembled underneath her banks.  --Shak.

   4. An elevation, or rising ground, under the sea; a shoal,
      shelf, or shallow; as, the banks of Newfoundland.

   5. (Mining)
      (a) The face of the coal at which miners are working.
      (b) A deposit of ore or coal, worked by excavations above
          water level.
      (c) The ground at the top of a shaft; as, ores are brought
          to bank.

   {Bank beaver} (Zo["o]l.), the otter. [Local, U.S.]

   {Bank swallow}, a small American and European swallow
      ({Clivicola riparia}) that nests in a hole which it
      excavates in a bank.

Bank swallow \Bank" swal"low\
   See under 1st {Bank}, n.

Source : WordNet®

bank swallow
     n : swallow of the northern hemisphere that nests in tunnels dug
         in clay or sand banks [syn: {bank martin}, {sand martin},
          {Riparia riparia}]