The Collaborative International Dictionary of English v.0.48:

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.
      [1913 Webster]

            They cast up a bank against the city. --2 Sam. xx.
                                                  15.
      [1913 Webster]

   2. A steep acclivity, as the slope of a hill, or the side of
      a ravine.
      [1913 Webster]

   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.
      [1913 Webster]

            Tiber trembled underneath her banks.  --Shak.
      [1913 Webster]

   4. An elevation, or rising ground, under the sea; a shoal,
      shelf, or shallow; as, the banks of Newfoundland.
      [1913 Webster]

   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.
          [1913 Webster]

   6. (A["e]ronautics) The lateral inclination of an
      a["e]roplane as it rounds a curve; as, a bank of 45[deg]
      is easy; a bank of 90[deg] is dangerous.
      [Webster 1913 Suppl.]

   7. A group or series of objects arranged near together; as, a
      bank of electric lamps, etc.
      [Webster 1913 Suppl.]

   8. The tilt of a roadway or railroad, at a curve in the road,
      designed to counteract centrifugal forces acting on
      vehicles moving rapiudly around the curve, thus reducing
      the danger of overturning during a turn.
      [PJC]

   Bank beaver (Zool.), 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.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Bank swallow \Bank" swal"low\
   See under 1st Bank, n.
   [1913 Webster]

WordNet (r) 3.0 (2006):

bank swallow
    n 1: swallow of the northern hemisphere that nests in tunnels
         dug in clay or sand banks [syn: bank martin, bank
         swallow, sand martin, Riparia riparia]