资料来源 : Webster's Revised Unabridged Dictionary (1913)

Ivy \I"vy\, n.; pl. {Ivies}. [AS. [=i]fig; akin to OHG. ebawi,
   ebah, G. epheu.] (Bot.)
   A plant of the genus {Hedera} ({H. helix}), common in Europe.
   Its leaves are evergreen, dark, smooth, shining, and mostly
   five-pointed; the flowers yellowish and small; the berries
   black or yellow. The stem clings to walls and trees by
   rootlike fibers.

         Direct The clasping ivy where to climb.  --Milton.

         Ye myrtles brown, with ivy never sere.   --Milton.

   {American ivy}. (Bot.) See {Virginia creeper}.

   {English ivy} (Bot.), a popular name in America for the ivy
      proper ({Hedera helix}).

   {German ivy} (Bot.), a creeping plant, with smooth, succulent
      stems, and fleshy, light-green leaves; a species of
      {Senecio} ({S. scandens}).

   {Ground ivy}. (Bot.) Gill ({Nepeta Glechoma}).

   {Ivy bush}. (Bot.) See {Mountain laurel}, under {Mountain}.
      

   {Ivy owl} (Zo["o]l.), the barn owl.

   {Ivy tod} (Bot.), the ivy plant. --Tennyson.

   {Japanese ivy} (Bot.), a climbing plant ({Ampelopsis
      tricuspidata}), closely related to the Virginia creeper.
      

   {Poison ivy} (Bot.), an American woody creeper ({Rhus
      Toxicodendron}), with trifoliate leaves, and
      greenish-white berries. It is exceedingly poisonous to the
      touch for most persons.

   {To pipe in an ivy leaf}, to console one's self as best one
      can. [Obs.] --Chaucer.

   {West Indian ivy}, a climbing plant of the genus
      {Marcgravia}.

Poison \Poi"son\, n. [F. poison, in Old French also, a potion,
   fr. L. potio a drink, draught, potion, a poisonous draught,
   fr. potare to drink. See {Potable}, and cf. {Potion}.]
   1. Any agent which, when introduced into the animal organism,
      is capable of producing a morbid, noxious, or deadly
      effect upon it; as, morphine is a deadly poison; the
      poison of pestilential diseases.

   2. That which taints or destroys moral purity or health; as,
      the poison of evil example; the poison of sin.

   {Poison ash}. (Bot.)
      (a) A tree of the genus {Amyris} ({A. balsamifera}) found
          in the West Indies, from the trunk of which a black
          liquor distills, supposed to have poisonous qualities.
      (b) The poison sumac ({Rhus venenata}). [U. S.]

   {Poison dogwood} (Bot.), poison sumac.

   {Poison fang} (Zo["o]l.), one of the superior maxillary teeth
      of some species of serpents, which, besides having the
      cavity for the pulp, is either perforated or grooved by a
      longitudinal canal, at the lower end of which the duct of
      the poison gland terminates. See Illust. under {Fang}.

   {Poison gland} (Biol.), a gland, in animals or plants, which
      secretes an acrid or venomous matter, that is conveyed
      along an organ capable of inflicting a wound.

   {Poison hemlock} (Bot.), a poisonous umbelliferous plant
      ({Conium maculatum}). See {Hemlock}.

   {Poison ivy} (Bot.), a poisonous climbing plant ({Rhus
      Toxicodendron}) of North America. It is common on stone
      walls and on the trunks of trees, and has trifoliate,
      rhombic-ovate, variously notched leaves. Many people are
      poisoned by it, if they touch the leaves. See {Poison
      sumac}. Called also {poison oak}, and {mercury}.

   {Poison nut}. (Bot.)
      (a) Nux vomica.
      (b) The tree which yields this seed ({Strychnos
          Nuxvomica}). It is found on the Malabar and Coromandel
          coasts.

   {Poison oak} (Bot.), the poison ivy; also, the more shrubby
      {Rhus diversiloba} of California and Oregon.

   {Poison sac}. (Zo["o]l.) Same as {Poison gland}, above. See
      Illust. under {Fang}.

   {Poison sumac} (Bot.), a poisonous shrub of the genus {Rhus}
      ({R. venenata}); -- also called {poison ash}, {poison
      dogwood}, and {poison elder}. It has pinnate leaves on
      graceful and slender common petioles, and usually grows in
      swampy places. Both this plant and the poison ivy ({Rhus
      Toxicodendron}) have clusters of smooth greenish white
      berries, while the red-fruited species of this genus are
      harmless. The tree ({Rhus vernicifera}) which yields the
      celebrated Japan lacquer is almost identical with the
      poison sumac, and is also very poisonous. The juice of the
      poison sumac also forms a lacquer similar to that of
      Japan.

   Syn: Venom; virus; bane; pest; malignity.

   Usage: {Poison}, {Venom}. Poison usually denotes something
          received into the system by the mouth, breath, etc.
          Venom is something discharged from animals and
          received by means of a wound, as by the bite or sting
          of serpents, scorpions, etc. Hence, venom specifically
          implies some malignity of nature or purpose.

资料来源 : WordNet®

poison ivy
     n 1: dermatitis resulting from contact with the poison ivy plant;
          "my poison ivy is drying up"
     2: climbing plant common in eastern and central United States
        with ternate leaves and greenish flowers followed by white
        berries; yields an irritating oil that causes a rash on
        contact [syn: {markweed}, {poison mercury}, {poison oak},
        {Toxicodendron radicans}, {Rhus radicans}]