[1] : The Collaborative International Dictionary of English v.0.48

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.
      1913 webster

   2. that which taints or destroys moral purity or health; as,
      the poison of evil example; the poison of sin.
      1913 webster

   poison ash. bot.
      a a tree of the genus amyris amyris 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 zool., 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 formerly
      rhus toxicodendron, or rhus radicans, now classified
      as toxicodendron radicans of north america. it is
      common as a climbing vine, especially found on tree
      trunks, or walls, or as a low, spreading vine or as a
      shrub. as a low vine it grows well in lightly shaded
      areas, recognizable by growing in clusters of three
      leaves. its leaves are trifoliate, rhombic-ovate, and
      variously notched. its form varies slightly from location
      to location, leading to some speculation that it may
      consist of more than one species. many people are poisoned
      by it, though some appear resistant to its effects.
      touching the leaves may leave a residue of an oil on the
      skin, and if not washed off quickly, sensitive areas of
      skin become reddened and develop multiple small blisters,
      lasting for several days to several weeks, and causing a
      persistent itch. the toxic reaction is due to an oil,
      present in all parts of the plant except the pollen,
      called urushiol, the active component of which is the
      compound pentadecylacatechol according to a

      href="http:/www.jaxmed.com/articles/diseases/poison_ivy_dermatitis.htm">charles
      h. booras. see poison sumac. it is related to poison
      oak, and is also called 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., a dermatitis-producing plant often
      lumped together with the poison ivy toxicodendron
      radicans in common terminology, but more properly
      distinguished as the more shrubby toxicodendron
      quercifolium syn. toxicodendron diversilobum, common
      in california and oregon. opinion varies as to whether the
      poison oak and poison ivy are only variants of a single
      species. see poison ivy, above.

   poison sac. zool. same as poison gland, above. see
      illust. under fang.

   poison sumac bot., a poisonous shrub formerly considered
      to be of the genus rhus rhus venenata, but now
      classified as toxicodendron vernix; -- 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 toxicodendron radicans, formerly 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.
      1913 webster +pjc

   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.
          1913 webster
see also:
potable potion poison ash amyris amyris balsamifera rhus venenata 
poison dogwood poison fang fang poison gland poison hemlock 
conium maculatum hemlock poison ivy rhus toxicodendron rhus radicans 
toxicodendron radicans urushiol pentadecylacatechol poison sumac poison oak 
mercury poison nut strychnos nuxvomica poison oak toxicodendron radicans 
toxicodendron quercifolium toxicodendron diversilobum poison ivy poison sac rhus 
toxicodendron vernix poison ash poison dogwood poison elder rhus toxicodendron 
rhus vernicifera poison venom 

[2] : The Collaborative International Dictionary of English v.0.48

poison \poi"son\, v. t. imp.  p. p. poisoned; p. pr.  vb.
   n. poisoning. cf. of. poisonner, f. empoissoner, l.
   potionare to give to drink. see poison, n.
   1913 webster
   1. to put poison upon or into; to infect with poison; as, to
      poison an arrow; to poison food or drink. "the ingredients
      of our poisoned chalice." --shak.
      1913 webster

   2. to injure or kill by poison; to administer poison to.
      1913 webster

            if you poison us, do we not die ?     --shak.
      1913 webster

   3. to taint; to corrupt; to vitiate; as, vice poisons
      happiness; slander poisoned his mind.
      1913 webster

            whispering tongues can poison truth.  --coleridge.
      1913 webster
see also:
poisoned poisoning poison 

[3] : The Collaborative International Dictionary of English v.0.48

poison \poi"son\, v. i.
   to act as, or convey, a poison.
   1913 webster

         tooth that poisons if it bite.           --shak.
   1913 webster

[4] : WordNet (r) 2.0

poison
     n 1: any substance that causes injury or illness or death of a
          living organism syn: poisonous substance
     2: anything that harms or destroys; "the poison of fascism"
     v 1: spoil as if by poison; "poison someone's mind"; "poison the
          atmosphere in the office"
     2: kill by its poison; "this mushrooms can kill"
     3: kill with poison; "she poisoned her husband"
     4: add poison to; "her husband poisoned her drink in order to
        kill her" syn: envenom
     5: administer poison to; "she poisoned her husband but he did
        not die"
see also:
poisonous substance envenom 

[5] : Moby Thesaurus II by Grady Ward, 1.0

282 moby thesaurus words for "poison":
   cain, ddd, ddt, paris green, abomination, abuse, acaricide,
   activate, adulterate, adulteration, afflict, aggrieve, alloy,
   annihilate, anthelmintic, antibiotic, antimony, antiseptic, apache,
   arsenic, arsenic trioxide, assassin, assassinator, atrocity, bad,
   bane, befoul, befoulment, bereave of life, beryllium, bewitch,
   bichloride of mercury, blight, bloodletter, bloodshedder, bravo,
   bug bomb, burker, butcher, button man, cadmium, cancer, canker,
   cannibal, carbamate insecticide, carbolic acid, carbon monoxide,
   carbon tetrachloride, carry away, carry off, charge, cheapen,
   chemosterilant, chlorinated hydrocarbon insecticide, chlorine,
   chloroform, coarsen, communicability, condemn, confound,
   contact poison, contagion, contagiousness, contaminate,
   contamination, corrupt, corruption, crucify, crying evil, curse,
   cut down, cut off, cutthroat, cyanide, damage, deadliness, debase,
   debauch, defile, defilement, deflower, defoliant, degenerate,
   degrade, demoralize, denature, deprave, deprive of life, desecrate,
   desperado, despoil, despoliation, destroy, destruction,
   destructiveness, detriment, devalue, disadvantage, disinfectant,
   dispatch, dispose of, disserve, distort, distress, do a mischief,
   do away with, do evil, do for, do ill, do to death, do wrong,
   do wrong by, doom, embalming fluid, empoison, end, envenom,
   eradicant, eradicator, evil, execute, executioner, exterminate,
   exterminator, finish, finish off, formaldehyde, fumigant,
   fungicide, garroter, germicide, get into trouble, gorilla,
   grievance, gun, gunman, gunsel, harass, harm, hatchet man, havoc,
   head-hunter, herbicide, hex, hit man, homicidal maniac, homicide,
   hurt, hydrocyanic acid, hyoscyamine, ill, immolate, impair, infect,
   infection, infectiousness, infectivity, injure, injury,
   insect powder, insecticide, irradiate, jinx, kill, killer,
   launch into eternity, lead, liquidate, lynch, make away with,
   malignancy, maltreat, man-eater, man-killer, manslayer, martyr,
   martyrize, massacrer, matador, menace, mephitic, mephitis,
   mercuric chloride, mercury, miasma, microbicide, mischief,
   mistreat, misuse, miticide, molest, murder, murderer, mustard gas,
   nicotine, noxiousness, organic chlorine,
   organic phosphate insecticide, outrage, panther piss, persecute,
   pervert, pesticide, pestilence, phenol, plague, play havoc with,
   play hob with, poison gas, poisoner, poisonousness, pollute,
   pollution, prejudice, prostitute, prussic acid, purge, put away,
   put down, put to death, put to sleep, radiumize, rat poison,
   ravage, ravish, remove from life, roach paste, roach powder,
   rodenticide, rotgut, sacrifice, savage, scathe, selenium, shellac,
   slaughterer, slay, slayer, sophistication, stain, starve,
   stomach poison, strangler, strychnine, subvert, systemic,
   systemic insecticide, taint, take life, take off, the worst,
   threaten, thug, torment, torpedo, torture, toxic, toxicant,
   toxicity, toxin, trigger man, twist, ulcerate, venin, venom,
   venomous, venomousness, vermicide, vexation, violate, virulence,
   virulency, virulent, virus, vitiate, vulgarize, warp, weed killer,
   woe, wound, wreak havoc on, wrong

[6] : Easton's 1897 Bible Dictionary

poison
   1. heb. hemah, "heat," the poison of certain venomous reptiles
   deut. 32:24, 33; job 6:4; ps. 58:4, causing inflammation.
   
     2. heb. rosh, "a head," a poisonous plant deut. 29:18,
   growing luxuriantly hos. 10:4, of a bitter taste ps. 69:21;
   lam. 3:5, and coupled with wormwood; probably the poppy. this
   word is rendered "gall", q.v., deut. 29:18; 32:33; ps. 69:21;
   jer. 8:14, etc., "hemlock" hos. 10:4; amos 6:12, and "poison"
   job 20:16, "the poison of asps," showing that the _rosh_ was
   not exclusively a vegetable poison.
   
     3. in rom. 3:13 comp. job 20:16; ps. 140:3, james 3:8, as
   the rendering of the greek ios.
   

[7] : Bouvier's Law Dictionary, Revised 6th Ed (1856)

poison, crim. law. those substances which, when applied to the organs of the 
body, are capable of altering or destroying, in a majority of cases, some or 
all of the functions necessary to life, are called poisons. 3 fodere, traite 
de med. leg. 449; guy, med. jur. 520. 
     2. when administered with a felonious intent of committing, murder, if. 
death ensues, it is murder the most detestable, because it can of all 
others, be least prevented by manhood or forethought. it is a deliberate act 
necessarily implying malice. 1 russ. cr. 429. for the signs which indicate 
poisoning, vide 2 beck's med. jurisp. ch. 16, p. 236, et seq.; cooper's med. 
jurisp. 47; ryan's med. jurisp. ch. 15, p. 202, et seq.; traill, med. jur. 
109. 

Poison >> P Words
Poison, definition of term: Poison
poison_pag1.html

Poison Pill >> P Words
Poison Pill, definition of term: Poison Pill
poison+pill_pag1.html

Poison Ivy >> P Words
Poison Ivy, definition of term: Poison Ivy
poison+ivy_pag1.html

Poison Oak >> P Words
Poison Oak, definition of term: Poison Oak
poison+oak_pag1.html