The Collaborative International Dictionary of English v.0.48:

Goldfinch \Gold"finch`\, n. [AS. goldfinc. See Gold, and
   Finch.] (Zool.)
   (a) A beautiful bright-colored European finch (Carduelis
       elegans). The name refers to the large patch of yellow
       on the wings. The front of the head and throat are bright
       red; the nape, with part of the wings and tail, black; --
       called also goldspink, goldie, fool's coat,
       drawbird, draw-water, thistle finch, and sweet
       William.
   (b) The yellow-hammer.
   (c) A small American finch (Spinus tristis); the thistle
       bird.
       [1913 Webster]

   Note: The name is also applied to other yellow finches, esp.
         to several additional American species of Spinus.
         [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Sweet \Sweet\, a. [Compar. Sweeter; superl. Sweetest.] [OE.
   swete, swote, sote, AS. sw[=e]te; akin to OFries. sw[=e]te,
   OS. sw[=o]ti, D. zoet, G. s["u]ss, OHG. suozi, Icel. saetr,
   soetr, Sw. s["o]t, Dan. s["o]d, Goth. suts, L. suavis, for
   suadvis, Gr. ?, Skr. sv[=a]du sweet, svad, sv[=a]d, to
   sweeten. [root]175. Cf. Assuage, Suave, Suasion.]
   1. Having an agreeable taste or flavor such as that of sugar;
      saccharine; -- opposed to sour and bitter; as, a sweet
      beverage; sweet fruits; sweet oranges.
      [1913 Webster]

   2. Pleasing to the smell; fragrant; redolent; balmy; as, a
      sweet rose; sweet odor; sweet incense.
      [1913 Webster]

            The breath of these flowers is sweet to me.
                                                  --Longfellow.
      [1913 Webster]

   3. Pleasing to the ear; soft; melodious; harmonious; as, the
      sweet notes of a flute or an organ; sweet music; a sweet
      voice; a sweet singer.
      [1913 Webster]

            To make his English sweet upon his tongue.
                                                  --Chaucer.
      [1913 Webster]

            A voice sweet, tremulous, but powerful. --Hawthorne.
      [1913 Webster]

   4. Pleasing to the eye; beautiful; mild and attractive; fair;
      as, a sweet face; a sweet color or complexion.
      [1913 Webster]

            Sweet interchange
            Of hill and valley, rivers, woods, and plains.
                                                  --Milton.
      [1913 Webster]

   5. Fresh; not salt or brackish; as, sweet water. --Bacon.
      [1913 Webster]

   6. Not changed from a sound or wholesome state. Specifically:
      (a) Not sour; as, sweet milk or bread.
      (b) Not state; not putrescent or putrid; not rancid; as,
          sweet butter; sweet meat or fish.
          [1913 Webster]

   7. Plaesing to the mind; mild; gentle; calm; amiable;
      winning; presuasive; as, sweet manners.
      [1913 Webster]

            Canst thou bind the sweet influence of Pleiades?
                                                  --Job xxxviii.
                                                  31.
      [1913 Webster]

            Mildness and sweet reasonableness is the one
            established rule of Christian working. --M. Arnold.
      [1913 Webster]

   Note: Sweet is often used in the formation of self-explaining
         compounds; as, sweet-blossomed, sweet-featured,
         sweet-smelling, sweet-tempered, sweet-toned, etc.
         [1913 Webster]

   Sweet alyssum. (Bot.) See Alyssum.

   Sweet apple. (Bot.)
      (a) Any apple of sweet flavor.
      (b) See Sweet-sop.

   Sweet bay. (Bot.)
      (a) The laurel (Laurus nobilis).
      (b) Swamp sassafras.

   Sweet calabash (Bot.), a plant of the genus Passiflora
      (Passiflora maliformis) growing in the West Indies, and
      producing a roundish, edible fruit, the size of an apple.


   Sweet cicely. (Bot.)
      (a) Either of the North American plants of the
          umbelliferous genus Osmorrhiza having aromatic roots
          and seeds, and white flowers. --Gray.
      (b) A plant of the genus Myrrhis (Myrrhis odorata)
          growing in England.

   Sweet calamus, or Sweet cane. (Bot.) Same as Sweet
      flag, below.

   Sweet Cistus (Bot.), an evergreen shrub (Cistus Ladanum)
      from which the gum ladanum is obtained.

   Sweet clover. (Bot.) See Melilot.

   Sweet coltsfoot (Bot.), a kind of butterbur (Petasites
      sagittata) found in Western North America.

   Sweet corn (Bot.), a variety of the maize of a sweet taste.
      See the Note under Corn.

   Sweet fern (Bot.), a small North American shrub (Comptonia
      asplenifolia syn. Myrica asplenifolia) having
      sweet-scented or aromatic leaves resembling fern leaves.


   Sweet flag (Bot.), an endogenous plant (Acorus Calamus)
      having long flaglike leaves and a rootstock of a pungent
      aromatic taste. It is found in wet places in Europe and
      America. See Calamus, 2.

   Sweet gale (Bot.), a shrub (Myrica Gale) having bitter
      fragrant leaves; -- also called sweet willow, and Dutch
      myrtle. See 5th Gale.

   Sweet grass (Bot.), holy, or Seneca, grass.

   Sweet gum (Bot.), an American tree (Liquidambar
      styraciflua). See Liquidambar.

   Sweet herbs, fragrant herbs cultivated for culinary
      purposes.

   Sweet John (Bot.), a variety of the sweet William.

   Sweet leaf (Bot.), horse sugar. See under Horse.

   Sweet marjoram. (Bot.) See Marjoram.

   Sweet marten (Zool.), the pine marten.

   Sweet maudlin (Bot.), a composite plant (Achillea
      Ageratum) allied to milfoil.

   Sweet oil, olive oil.

   Sweet pea. (Bot.) See under Pea.

   Sweet potato. (Bot.) See under Potato.

   Sweet rush (Bot.), sweet flag.

   Sweet spirits of niter (Med. Chem.) See Spirit of nitrous
      ether, under Spirit.

   Sweet sultan (Bot.), an annual composite plant (Centaurea
      moschata), also, the yellow-flowered (Centaurea
      odorata); -- called also sultan flower.

   Sweet tooth, an especial fondness for sweet things or for
      sweetmeats. [Colloq.]

   Sweet William.
      (a) (Bot.) A species of pink (Dianthus barbatus) of many
          varieties.
      (b) (Zool.) The willow warbler.
      (c) (Zool.) The European goldfinch; -- called also sweet
          Billy. [Prov. Eng.]

   Sweet willow (Bot.), sweet gale.

   Sweet wine. See Dry wine, under Dry.

   To be sweet on, to have a particular fondness for, or
      special interest in, as a young man for a young woman.
      [Colloq.] --Thackeray.
      [1913 Webster]

   Syn: Sugary; saccharine; dulcet; luscious.
        [1913 Webster]

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]

WordNet (r) 3.0 (2006):

sweet William
    n 1: Eurasian pink widely cultivated for its flat-topped dense
         clusters of varicolored flowers [syn: sweet William,
         Dianthus barbatus]