The Collaborative International Dictionary of English v.0.48:

Willow \Wil"low\, n. [OE. wilowe, wilwe, AS. wilig, welig; akin
   to OD. wilge, D. wilg, LG. wilge. Cf. Willy.]
   [1913 Webster]
   1. (Bot.) Any tree or shrub of the genus Salix, including
      many species, most of which are characterized often used
      as an emblem of sorrow, desolation, or desertion. "A
      wreath of willow to show my forsaken plight." --Sir W.
      Scott. Hence, a lover forsaken by, or having lost, the
      person beloved, is said to wear the willow.
      [1913 Webster]

            And I must wear the willow garland
            For him that's dead or false to me.   --Campbell.
      [1913 Webster]

   2. (Textile Manuf.) A machine in which cotton or wool is
      opened and cleansed by the action of long spikes
      projecting from a drum which revolves within a box studded
      with similar spikes; -- probably so called from having
      been originally a cylindrical cage made of willow rods,
      though some derive the term from winnow, as denoting the
      winnowing, or cleansing, action of the machine. Called
      also willy, twilly, twilly devil, and devil.
      [1913 Webster]

   Almond willow, Pussy willow, Weeping willow. (Bot.) See
      under Almond, Pussy, and Weeping.

   Willow biter (Zool.) the blue tit. [Prov. Eng.]

   Willow fly (Zool.), a greenish European stone fly
      (Chloroperla viridis); -- called also yellow Sally.

   Willow gall (Zool.), a conical, scaly gall produced on
      willows by the larva of a small dipterous fly (Cecidomyia
      strobiloides).

   Willow grouse (Zool.), the white ptarmigan. See
      ptarmigan.

   Willow lark (Zool.), the sedge warbler. [Prov. Eng.]

   Willow ptarmigan (Zool.)
      (a) The European reed bunting, or black-headed bunting.
          See under Reed.
      (b) A sparrow (Passer salicicolus) native of Asia,
          Africa, and Southern Europe.

   Willow tea, the prepared leaves of a species of willow
      largely grown in the neighborhood of Shanghai, extensively
      used by the poorer classes of Chinese as a substitute for
      tea. --McElrath.

   Willow thrush (Zool.), a variety of the veery, or Wilson's
      thrush. See Veery.

   Willow warbler (Zool.), a very small European warbler
      (Phylloscopus trochilus); -- called also bee bird,
      haybird, golden wren, pettychaps, sweet William,
      Tom Thumb, and willow wren.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Willow \Wil"low\, v. t.
   To open and cleanse, as cotton, flax, or wool, by means of a
   willow. See Willow, n., 2.
   [1913 Webster]

WordNet (r) 3.0 (2006):

willow
    n 1: any of numerous deciduous trees and shrubs of the genus
         Salix [syn: willow, willow tree]
    2: a textile machine having a system of revolving spikes for
       opening and cleaning raw textile fibers

U.S. Gazetteer Places (2000):

Willow, AK -- U.S. Census Designated Place in Alaska
   Population (2000):    1658
   Housing Units (2000): 1530
   Land area (2000):     684.817388 sq. miles (1773.668818 sq. km)
   Water area (2000):    8.042330 sq. miles (20.829537 sq. km)
   Total area (2000):    692.859718 sq. miles (1794.498355 sq. km)
   FIPS code:            85280
   Located within:       Alaska (AK), FIPS 02
   Location:             61.769345 N, 149.991065 W
   ZIP Codes (1990):     99688
   Note: some ZIP codes may be omitted esp. for suburbs.
   Headwords:
    Willow, AK
    Willow


U.S. Gazetteer Places (2000):

Willow, OK -- U.S. town in Oklahoma
   Population (2000):    114
   Housing Units (2000): 66
   Land area (2000):     0.264673 sq. miles (0.685499 sq. km)
   Water area (2000):    0.000000 sq. miles (0.000000 sq. km)
   Total area (2000):    0.264673 sq. miles (0.685499 sq. km)
   FIPS code:            81300
   Located within:       Oklahoma (OK), FIPS 40
   Location:             35.052527 N, 99.509531 W
   ZIP Codes (1990):     73673
   Note: some ZIP codes may be omitted esp. for suburbs.
   Headwords:
    Willow, OK
    Willow