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

monkey \mon"key\, n.; pl. monkeys. cf. oit. monicchio, it.
   monnino, dim. of monna an ape, also dame, mistress, contr.
   fr. madonna. see madonna.
   1. zool.
      a in the most general sense, any one of the quadrumana,
          including apes, baboons, and lemurs.
      b any species of quadrumana, except the lemurs.
      c any one of numerous species of quadrumana esp. such
          as have a long tail and prehensile feet exclusive of
          apes and baboons.
          1913 webster

   note: the monkeys are often divided into three groups: a
         catarrhines, or simidae. these have an oblong head,
         with the oblique flat nostrils near together. some have
         no tail, as the apes. all these are natives of the old
         world. b platyrhines, or cebidae. these have a
         round head, with a broad nasal septum, so that the
         nostrils are wide apart and directed downward. the tail
         is often prehensile, and the thumb is short and not
         opposable. these are natives of the new world. c
         strepsorhines, or lemuroidea. these have a pointed
         head with curved nostrils. they are natives of southern
         asia, africa, and madagascar.
         1913 webster

   2. a term of disapproval, ridicule, or contempt, as for a
      mischievous child.
      1913 webster

            this is the monkey's own giving out; she is
            persuaded i will marry her.           --shak.
      1913 webster

   3. the weight or hammer of a pile driver, that is, a very
      heavy mass of iron, which, being raised on high, falls on
      the head of the pile, and drives it into the earth; the
      falling weight of a drop hammer used in forging.
      1913 webster

   4. a small trading vessel of the sixteenth century.
      1913 webster

   monkey boat. naut.
      a a small boat used in docks.
      b a half-decked boat used on the river thames.

   monkey block naut., a small single block strapped with a
      swivel. --r. h. dana, jr.

   monkey flower bot., a plant of the genus mimulus; -- so
      called from the appearance of its gaping corolla. --gray.

   monkey gaff naut., a light gaff attached to the topmast
      for the better display of signals at sea.

   monkey jacket, a short closely fitting jacket, worn by
      sailors.

   monkey rail naut., a second and lighter rail raised about
      six inches above the quarter rail of a ship.

   monkey shine, monkey trick. slang, u.s.

   monkey trick, a mischievous prank. --saintsbury.

   monkey wheel. see gin block, under 5th gin.
      1913 webster
see also:
monkeys madonna a catarrhines simidae b 
platyrhines cebidae c strepsorhines lemuroidea 
monkey boat monkey block monkey flower mimulus monkey gaff 
monkey jacket monkey rail monkey shine monkey trick monkey wheel 
gin block gin 

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

monkey \mon"key\, v. t.  i.
   to act or treat as a monkey does; to ape; to act in a
   grotesque or meddlesome manner.
   1913 webster

   to monkey with, to monkey around with, to handle in a
      meddlesome manner. colloq.
      1913 webster +pjc
see also:
to monkey with to monkey around with 

[3] : WordNet (r) 2.0

monkey
     n 1: any of various long-tailed primates excluding the
          prosimians
     2: one who is playfully mischievous syn: imp, scamp, rascal,
         rapscallion, scalawag, scallywag
     v 1: play around with or alter or falsify, usually secretively or
          dishonestly; "someone tampered with the documents on my
          desk"; "the reporter fiddle with the facts" syn: tamper,
           fiddle
     2: do random, unplanned work or activities or spend time idly;
        "the old lady is usually mucking about in her little
        house" syn: putter, mess around, potter, tinker,
        monkey around, muck about, muck around
see also:
imp scamp rascal rapscallion scalawag scallywag 
tamper fiddle putter mess around potter 
tinker monkey around muck about muck around 

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

204 moby thesaurus words for "monkey":
   cape polecat, chiroptera, irish, lagomorpha, primates, rodentia,
   ape, ass, babe, bad temper, bantam, bar, bawbee, bear, boob, butt,
   byword, byword of reproach, cavy, chimp, chimpanzee, chump, cinch,
   conformist, coon, copier, copy, copycat, copyist, coquet,
   counterfeiter, credulous person, crown, cuckoo, cull, dabble,
   dally, dander, derision, devil, dissembler, dissimulator, dollar,
   dupe, duplicate, easy mark, easy pickings, echo, echoer, echoist,
   fair game, faker, fall guy, farthing, ferret, fiddle, fiddle with,
   fiddle-faddle, fidget with, figure of fun, finger with, fish,
   fiver, flirt, florin, fool, fool around, fool with, forger,
   foumart, fourpence, fourpenny, fribble, frivol, game, gamin,
   gazingstock, glutton, goat, gobe-mouches, greener, greenhorn,
   greeny, groat, groundhog, gudgeon, guinea, guinea pig, gull,
   half crown, half dollar, halfpenny, hedgehog, horse around,
   hypocrite, idle, imitate, imitator, imp, impersonate, impersonator,
   impostor, innocent, interfere with, jerk off, jest, jestingstock,
   joke, kid around, laughingstock, leadpipe cinch, little, loiter,
   mag, mark, meddle with, meg, mess around, mime, mimer, mimic,
   mimicker, mischief-maker, mite, mocker, mockery, mockingbird, monk,
   monkey around, mousehound, new pence, np, opossum, p, parrot,
   patsy, pence, penny, petite, phony, piddle, pigeon, plagiarist,
   play, play around, play with, plaything, polecat, poll-parrot,
   polly, polly-parrot, pony, porcupine, poseur, possum, potter,
   pound, prairie dog, primate, prize sap, pushover, putter, quid,
   quill pig, raccoon, rapscallion, rascal, sap, saphead, scamp,
   schlemiel, sheep, shilling, simian, simulator, sitting duck,
   sixpence, skunk, smallish, smatter, stock, stooge, sucker,
   tamper with, target, temper, tenner, threepence, threepenny bit,
   thrippence, tinker, toy, toy with, trifle, trusting soul, tuppence,
   twiddle, twopence, victim, weasel, whistle-pig, wolverine,
   woodchuck, zoril

[5] : THE DEVIL'S DICTIONARY ((C)1911 Released April 15 1993)

monkey, n.  an arboreal animal which makes itself at home in
genealogical trees.

Monkey >> M Words
Monkey, definition of term: Monkey
monkey_pag1.html

Monkey Wrench >> M Words
Monkey Wrench, definition of term: Monkey Wrench
monkey+wrench_pag1.html

Monkey Nut >> M Words
Monkey Nut, definition of term: Monkey Nut
monkey+nut_pag1.html

Monkey Jacket >> M Words
Monkey Jacket, definition of term: Monkey Jacket
monkey+jacket_pag1.html

Monkey Bridge >> M Words
Monkey Bridge, definition of term: Monkey Bridge
monkey+bridge_pag1.html

Monkey Bread >> M Words
Monkey Bread, definition of term: Monkey Bread
monkey+bread_pag1.html

Squirrel Monkey >> S Words
Squirrel Monkey, definition of term: Squirrel Monkey
squirrel+monkey_pag1.html

Spider Monkey >> S Words
Spider Monkey, definition of term: Spider Monkey
spider+monkey_pag1.html

Brass Monkey >> B Words
Brass Monkey, definition of term: Brass Monkey
brass+monkey_pag1.html