The Collaborative International Dictionary of English v.0.48:

Maim \Maim\, n. [Written in law language maihem, and
   mayhem.] [OF. mehaing. See Maim, v.]
   1. The privation of the use of a limb or member of the body,
      by which one is rendered less able to defend himself or to
      annoy his adversary.
      [1913 Webster]

   2. The privation of any necessary part; a crippling;
      mutilation; injury; deprivation of something essential.
      See Mayhem.
      [1913 Webster]

            Surely there is more cause to fear lest the want
            there of be a maim than the use of it a blemish.
                                                  --Hooker.
      [1913 Webster]

            A noble author esteems it to be a maim in history
            that the acts of Parliament should not be recited.
                                                  --Hayward.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Maim \Maim\ (m[=a]m), v. t. [imp. & p. p. Maimed (m[=a]md);p.
   pr. & vb. n. Maiming.] [OE. maimen, OF. mahaignier,
   mehaignier, meshaignier, cf. It. magagnare, LL. mahemiare,
   mahennare; perh. of Celtic origin; cf. Armor. mac'ha[~n]a to
   mutilate, m[=a]c'ha to crowd, press; or cf. OHG. mang[=o]n to
   lack, perh. akin to E. mangle to lacerate. Cf. Mayhem.]
   1. To deprive of the use of a limb, so as to render a person
      in fighting less able either to defend himself or to annoy
      his adversary.
      [1913 Webster]

            By the ancient law of England he that maimed any man
            whereby he lost any part of his body, was sentenced
            to lose the like part.                --Blackstone.
      [1913 Webster]

   2. To mutilate; to cripple; to injure; to disable; to impair.
      [1913 Webster]

            My late maimed limbs lack wonted might. --Spenser.
      [1913 Webster]

            You maimed the jurisdiction of all bishops. --Shak.
      [1913 Webster]

   Syn: To mutilate; mangle; cripple.
        [1913 Webster]

WordNet (r) 3.0 (2006):

maim
    v 1: injure or wound seriously and leave permanent disfiguration
         or mutilation; "people were maimed by the explosion"

Moby Thesaurus II by Grady Ward, 1.0:

99 Moby Thesaurus words for "maim":
   abrade, bark, batter, blemish, bloody, break, bugger, bung up,
   burn, castrate, chafe, check, chip, claw, crack, craze, cripple,
   cut, damage, de-energize, debilitate, defoliate, denude, disable,
   disenable, disfigure, dismember, drain, draw and quarter,
   emasculate, enfeeble, flay, fracture, fray, frazzle, fret, gall,
   gash, hamstring, harm, hobble, hors de combat, hurt, impair,
   inactivate, incapacitate, incise, injure, kibosh, lacerate, lame,
   make mincemeat of, mangle, massacre, maul, mayhem, mutilate, peel,
   pick to pieces, pierce, pull apart, puncture, put, queer,
   queer the works, rend, rip, run, rupture, sabotage, savage, scald,
   scorch, scotch, scrape, scratch, scuff, shred, skin, slash, slit,
   spike, sprain, stab, stick, strain, strip, take apart, tear,
   tear apart, tear to pieces, tear to tatters, traumatize, unfit,
   weaken, wing, wound, wreck, wrench



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

MAIM, pleadings. This is a technical word necessary to be introduced into
all indictments for mayhem; the words "feloniously did maim," must of
necessity be inserted, because no other word, or any circumlocution, will
answer the same purpose. 4 Inst. 118; Hawk. B. 2, c. 23, s. 17, 18, 77;
Hawk. B. 2, c. 25, s, 55; 1 Chit. Cr. Law, *244.