Source : Webster's Revised Unabridged Dictionary (1913)

Weed \Weed\, n. [OE. weed, weod, AS. we['o]d, wi['o]d, akin to
   OS. wiod, LG. woden the stalks and leaves of vegetables D.
   wieden to weed, OS. wiod[=o]n.]
   1. Underbrush; low shrubs. [Obs. or Archaic]

            One rushing forth out of the thickest weed.
                                                  --Spenser.

            A wild and wanton pard . . . Crouched fawning in the
            weed.                                 --Tennyson.

   2. Any plant growing in cultivated ground to the injury of
      the crop or desired vegetation, or to the disfigurement of
      the place; an unsightly, useless, or injurious plant.

            Too much manuring filled that field with weeds.
                                                  --Denham.

   Note: The word has no definite application to any particular
         plant, or species of plants. Whatever plants grow among
         corn or grass, in hedges, or elsewhere, and are useless
         to man, injurious to crops, or unsightly or out of
         place, are denominated weeds.

   3. Fig.: Something unprofitable or troublesome; anything
      useless.

   4. (Stock Breeding) An animal unfit to breed from.

   5. Tobacco, or a cigar. [Slang]

   {Weed hook}, a hook used for cutting away or extirpating
      weeds. --Tusser.

Weed \Weed\, n. [OE. wede, AS. w?de, w?d; akin to OS. w[=a]di,
   giw[=a]di, OFries, w?de, w?d, OD. wade, OHG. w[=a]t, Icel.
   v[=a]?, Zend vadh to clothe.]
   1. A garment; clothing; especially, an upper or outer
      garment. ``Low?ly shepherd's weeds.'' --Spenser. ``Woman's
      weeds.'' --Shak. ``This beggar woman's weed.'' --Tennyson.

            He on his bed sat, the soft weeds he wore Put off.
                                                  --Chapman.

   2. An article of dress worn in token of grief; a mourning
      garment or badge; as, he wore a weed on his hat;
      especially, in the plural, mourning garb, as of a woman;
      as, a widow's weeds.

            In a mourning weed, with ashes upon her head, and
            tears abundantly flowing.             --Milton.

Weed \Weed\, n.
   A sudden illness or relapse, often attended with fever, which
   attacks women in childbed. [Scot.]

Weed \Weed\, v. t. [imp. & p. p. {Weeded}; p. pr. & vb. n.
   {Weeding}.] [AS. we['o]dian. See 3d {Weed}.]
   1. To free from noxious plants; to clear of weeds; as, to
      weed corn or onions; to weed a garden.

   2. To take away, as noxious plants; to remove, as something
      hurtful; to extirpate. ``Weed up thyme.'' --Shak.

            Wise fathers . . . weeding from their children ill
            things.                               --Ascham.

            Revenge is a kind of wild justice, which the more
            man's nature runs to, the more ought law to weed it
            out.                                  --Bacon.

   3. To free from anything hurtful or offensive.

            He weeded the kingdom of such as were devoted to
            Elaiana.                              --Howell.

   4. (Stock Breeding) To reject as unfit for breeding purposes.

Source : WordNet®

weed
     v : clear of weeds; "weed the garden"

weed
     n 1: any plant that crowds out cultivated plants [ant: {cultivated
          plant}]
     2: street names for marijuana [syn: {pot}, {grass}, {green
        goddess}, {dope}, {gage}, {sess}, {sens}, {smoke}, {skunk},
         {locoweed}, {Mary Jane}]