The Collaborative International Dictionary of English v.0.48:

Plant \Plant\, n. [AS. plante, L. planta.]
   1. A vegetable; an organized living being, generally without
      feeling and voluntary motion, and having, when complete, a
      root, stem, and leaves, though consisting sometimes only
      of a single leafy expansion, or a series of cellules, or
      even a single cellule.
      [1913 Webster]

   Note: Plants are divided by their structure and methods of
         reproduction into two series, ph[ae]nogamous or
         flowering plants, which have true flowers and seeds,
         and cryptogamous or flowerless plants, which have no
         flowers, and reproduce by minute one-celled spores. In
         both series are minute and simple forms and others of
         great size and complexity.
         [1913 Webster] As to their mode of nutrition, plants
         may be considered as self-supporting and dependent.
         Self-supporting plants always contain chlorophyll, and
         subsist on air and moisture and the matter dissolved in
         moisture, and as a general rule they excrete oxygen,
         and use the carbonic acid to combine with water and
         form the material for their tissues. Dependent plants
         comprise all fungi and many flowering plants of a
         parasitic or saprophytic nature. As a rule, they have
         no chlorophyll, and subsist mainly or wholly on matter
         already organized, thus utilizing carbon compounds
         already existing, and not excreting oxygen. But there
         are plants which are partly dependent and partly
         self-supporting.
         [1913 Webster] The movements of climbing plants, of
         some insectivorous plants, of leaves, stamens, or
         pistils in certain plants, and the ciliary motion of
         zoospores, etc., may be considered a kind of voluntary
         motion.
         [1913 Webster]

   2. A bush, or young tree; a sapling; hence, a stick or staff.
      "A plant of stubborn oak." --Dryden.
      [1913 Webster]

   3. The sole of the foot. [R.] "Knotty legs and plants of
      clay." --B. Jonson.
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   4. (Com.) The whole machinery and apparatus employed in
      carrying on a trade or mechanical business; also,
      sometimes including real estate, and whatever represents
      investment of capital in the means of carrying on a
      business, but not including material worked upon or
      finished products; as, the plant of a foundry, a mill, or
      a railroad.
      [1913 Webster]

   5. A plan; an artifice; a swindle; a trick. [Slang]
      [1913 Webster]

            It was n't a bad plant, that of mine, on Fikey.
                                                  --Dickens.
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   6. (Zool.)
      (a) An oyster which has been bedded, in distinction from
          one of natural growth.
      (b) A young oyster suitable for transplanting. [Local,
          U.S.]
          [1913 Webster]
          [1913 Webster]

   Plant bug (Zool.), any one of numerous hemipterous insects
      which injure the foliage of plants, as Lygus lineolaris,
      which damages wheat and trees.

   Plant cutter (Zool.), a South American passerine bird of
      the genus Phytotoma, family Phytotomid[ae]. It has a
      serrated bill with which it cuts off the young shoots and
      buds of plants, often doing much injury.

   Plant louse (Zool.), any small hemipterous insect which
      infests plants, especially those of the families
      Aphid[ae] and Psyllid[ae]; an aphid.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Plant \Plant\, v. t. [imp. & p. p. Planted; p. pr. & vb. n.
   Planting.] [AS. plantian, L. plantare. See Plant, n.]
   1. To put in the ground and cover, as seed for growth; as, to
      plant maize.
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   2. To set in the ground for growth, as a young tree, or a
      vegetable with roots.
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            Thou shalt not plant thee a grove of any trees.
                                                  --Deut. xvi.
                                                  21.
      [1913 Webster]

   3. To furnish, or fit out, with plants; as, to plant a
      garden, an orchard, or a forest.
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   4. To engender; to generate; to set the germ of.
      [1913 Webster]

            It engenders choler, planteth anger.  --Shak.
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   5. To furnish with a fixed and organized population; to
      settle; to establish; as, to plant a colony.
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            Planting of countries like planting of woods.
                                                  --Bacon.
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   6. To introduce and establish the principles or seeds of; as,
      to plant Christianity among the heathen.
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   7. To set firmly; to fix; to set and direct, or point; as, to
      plant cannon against a fort; to plant a standard in any
      place; to plant one's feet on solid ground; to plant one's
      fist in another's face.
      [1913 Webster]

   8. To set up; to install; to instate.
      [1913 Webster]

            We will plant some other in the throne. --Shak.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Plant \Plant\, v. i.
   To perform the act of planting.
   [1913 Webster]

         I have planted; Apollos watered.         --1 Cor. iii.
                                                  6.
   [1913 Webster]

WordNet (r) 3.0 (2006):

plant
    n 1: buildings for carrying on industrial labor; "they built a
         large plant to manufacture automobiles" [syn: plant,
         works, industrial plant]
    2: (botany) a living organism lacking the power of locomotion
       [syn: plant, flora, plant life]
    3: an actor situated in the audience whose acting is rehearsed
       but seems spontaneous to the audience
    4: something planted secretly for discovery by another; "the
       police used a plant to trick the thieves"; "he claimed that
       the evidence against him was a plant"
    v 1: put or set (seeds, seedlings, or plants) into the ground;
         "Let's plant flowers in the garden" [syn: plant, set]
    2: fix or set securely or deeply; "He planted a knee in the back
       of his opponent"; "The dentist implanted a tooth in the gum"
       [syn: implant, engraft, embed, imbed, plant]
    3: set up or lay the groundwork for; "establish a new
       department" [syn: establish, found, plant,
       constitute, institute]
    4: place into a river; "plant fish"
    5: place something or someone in a certain position in order to
       secretly observe or deceive; "Plant a spy in Moscow"; "plant
       bugs in the dissident's apartment"
    6: put firmly in the mind; "Plant a thought in the students'
       minds" [syn: plant, implant]

Moby Thesaurus II by Grady Ward, 1.0:

258 Moby Thesaurus words for "plant":
   accouterments, adulterate, agent provocateur, amphibian,
   angiosperm, annual, apparatus, appliances, appointments,
   appurtenances, aquatic plant, armament, armory, arsenal,
   assembly line, assembly plant, assign, atomic energy plant, base,
   bed, biennial, bindery, boatyard, boilery, bookbindery, bosom,
   bottle up, brewery, brickyard, broadcast, build, build in, bury,
   bush, cache, cannery, capper, clawed, colonize, come-on man,
   conceal, confirm, conveniences, cook, cosmopolite, cover, creamery,
   cutting, dairy, deciduous plant, decoy, deep-dye, defense plant,
   define, denizen, deposit, dibble, dicot, dicotyledon, disseminate,
   distillery, dockyard, doctor, drill, duffel, dust, embed, embosom,
   empeople, engraft, engrave, entomb, entrench, ephemeral, equipage,
   equipment, establish, etch, evergreen, exotic, facilities,
   facility, factory, factory belt, factory district, fake,
   feeder plant, file and forget, fittings, fix, fixtures, flour mill,
   flower, flowering plant, footed, forest, found, foundry, fungus,
   furnishings, furniture, gametophyte, gear, ground, gymnosperm,
   herb, hide, hide away, hoofed, hydrophyte, impact, impedimenta,
   implant, impress, imprint, industrial park, industrial zone, infix,
   informant, informer, ingrain, inhabit, inhume, inject, inscribe,
   inseminate, insinuate, install, installations, inter, introduce,
   invest, jam, juggle, keep hidden, keep secret, kit, lay away,
   lay the foundation, load, lock up, lodge, machinery, main plant,
   manipulate, manufactory, manufacturing plant,
   manufacturing quarter, materiel, mill, mint, monocot, monocotyl,
   munition, munitions, munitions plant, occult, oil refinery, outfit,
   pack, packing house, paraphernalia, pedal, people, perennial,
   pitch, place, plantar, plumbing, polycot, polycotyl, polycotyledon,
   populate, position, pot, pottery, power plant, print,
   production line, push-button plant, put, put away, put in, put up,
   refinery, reforest, reset, retimber, retouch, rig, rigging, root,
   salt, sawmill, scatter, scatter seed, screen, seal up, seat,
   secret agent, secrete, seed, seed down, seed plant, seedling,
   seminate, set, set in, set out, set up, settle, settle in, shill,
   shipyard, shop, shrub, situate, sophisticate, sow, sow broadcast,
   spermatophyte, sporophyte, spy, stack, stamp, stash, station,
   stereotype, stock-in-trade, stool pigeon, stoolie, store away,
   stow away, subassembly plant, sugar refinery, tackle, taloned,
   tamper with, tannery, thallophyte, things, toed, tomb, transplant,
   tree, triennial, ungulate, utensils, vascular plant, vegetable,
   vest, vine, wedge, weed, winery, works, yard, yards