The Collaborative International Dictionary of English v.0.48:

gum tree \gum" tree`\ n.
   Any tree that exudes a gum, such as:
   (a) The black gum (Nyssa multiflora), one of the largest
       trees of the Southern States, bearing a small blue fruit,
       the favorite food of the opossum. Most of the large trees
       become hollow.
   (b) A tree of the genus Eucalyptus; a eucalypt. See
       Eucalpytus.
   (c) The sweet gum tree of the United States (Liquidambar
       styraciflua), a large and beautiful tree with pointedly
       lobed leaves and woody burlike fruit. It exudes an
       aromatic terebinthine juice.
   (d) The sour gum tree.
       [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Liquidambar \Liq"uid*am`bar\ (l[i^]k"w[i^]d*[a^]m`b[~e]r), n.
   [Liquid + amber.]
   1. (Bot.) A genus consisting of two species of tall trees
      having star-shaped leaves, and woody burlike fruit.
      Liquidambar styraciflua is the North American sweet
      qum, and Liquidambar Orientalis is found in Asia Minor.
      [1913 Webster]

   2. The balsamic juice which is obtained from these trees by
      incision. The liquid balsam of the Oriental tree is liquid
      storax.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Storax \Sto"rax\, n. [L. storax, styrax, Gr. ?. Cf. Styrax.]
   Any one of a number of similar complex resins obtained from
   the bark of several trees and shrubs of the Styrax family.
   The most common of these is liquid storax, a brown or gray
   semifluid substance of an agreeable aromatic odor and
   balsamic taste, sometimes used in perfumery, and in medicine
   as an expectorant.
   [1913 Webster]

   Note: A yellow aromatic honeylike substance, resembling, and
         often confounded with, storax, is obtained from the
         American sweet gum tree (Liquidambar styraciflua),
         and is much used as a chewing gum, called sweet gum,
         and liquid storax. Cf. Liquidambar.
         [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]

WordNet (r) 3.0 (2006):

Liquidambar styraciflua
    n 1: a North American tree of the genus Liquidambar having
         prickly spherical fruit clusters and fragrant sap [syn:
         sweet gum, sweet gum tree, bilsted, red gum,
         American sweet gum, Liquidambar styraciflua]