The Collaborative International Dictionary of English v.0.48:

nerve \nerve\ (n[~e]rv), n. [OE. nerfe, F. nerf, L. nervus, akin
   to Gr. ney^ron sinew, nerve; cf. neyra` string, bowstring;
   perh. akin to E. needle. Cf. Neuralgia.]
   1. (Anat.) One of the whitish and elastic bundles of fibers,
      with the accompanying tissues, which transmit nervous
      impulses between nerve centers and various parts of the
      animal body.
      [1913 Webster]

   Note: An ordinary nerve is made up of several bundles of
         nerve fibers, each bundle inclosed in a special sheath
         (the perineurium) and all bound together in a
         connective tissue sheath and framework (the epineurium)
         containing blood vessels and lymphatics.
         [1913 Webster]

   2. A sinew or a tendon. --Pope.
      [1913 Webster]

   3. Physical force or steadiness; muscular power and control;
      constitutional vigor.
      [1913 Webster]

            he led me on to mightiest deeds,
            Above the nerve of mortal arm.        --Milton.
      [1913 Webster]

   4. Steadiness and firmness of mind; self-command in personal
      danger, or under suffering; unshaken courage and
      endurance; coolness; pluck; resolution.
      [1913 Webster]

   5. Audacity; assurance. [Slang]
      [1913 Webster]

   6. (Bot.) One of the principal fibrovascular bundles or ribs
      of a leaf, especially when these extend straight from the
      base or the midrib of the leaf.
      [1913 Webster]

   7. (Zool.) One of the nervures, or veins, in the wings of
      insects.
      [1913 Webster]

   Nerve cell (Anat.), a neuron, one of the nucleated cells
      with which nerve fibers are connected; a ganglion cell
      is one type of nerve cell.

   Nerve fiber (Anat.), one of the fibers of which nerves are
      made up. These fibers are either medullated or
      nonmedullated. In both kinds the essential part is the
      translucent threadlike axis cylinder which is continuous
      the whole length of the fiber.

   Nerve stretching (Med.), the operation of stretching a
      nerve in order to remedy diseases such as tetanus, which
      are supposed to be influenced by the condition of the
      nerve or its connections.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Nerve \Nerve\ (n[~e]rv), v. t. [imp. & p. p. Nerved
   (n[~e]rvs); p. pr. & vb. n. Nerving.]
   To give strength or vigor to; to supply with force; as, fear
   nerved his arm.
   [1913 Webster]

WordNet (r) 3.0 (2006):

nerve
    n 1: any bundle of nerve fibers running to various organs and
         tissues of the body [syn: nerve, nervus]
    2: the courage to carry on; "he kept fighting on pure spunk";
       "you haven't got the heart for baseball" [syn: heart,
       mettle, nerve, spunk]
    3: impudent aggressiveness; "I couldn't believe her boldness";
       "he had the effrontery to question my honesty" [syn:
       boldness, nerve, brass, face, cheek]
    v 1: get ready for something difficult or unpleasant [syn:
         steel, nerve]

Moby Thesaurus II by Grady Ward, 1.0:

174 Moby Thesaurus words for "nerve":
   afferent neuron, animate, annoy, anxiety, aplomb, apprehension,
   assurance, assure, audacity, autonomic nervous system, axon,
   backbone, balance, balanced personality, balls, beef up, boldness,
   bolster, bottle, bottom, brace, brace up, brain, brashness, brass,
   bravery, brazenness, buck up, buttress, case harden,
   central nervous system, cerebral cortex, cheek, cheer, chirk up,
   chutzpah, confidence, confirm, constancy, cool, coolness, courage,
   craniosacral nervous system, crust, daring, dauntlessness,
   dendrite, determination, doughtiness, effector organ,
   efferent neuron, effrontery, embolden, encourage, equilibrium,
   face, fastness, fearlessness, firmness, fortify, fortitude,
   forwardness, fretfulness, fright, gall, ganglion, gird,
   gray matter, grit, gumption, guts, gutsiness, guttiness, harden,
   hardihood, hardiness, heart, heart of oak, hearten, homeostasis,
   hysteria, impertinence, imperturbability, importunacy,
   importunateness, impudence, insolence, inspire, inspirit,
   internuncial neuron, intestinal fortitude, intrepidity,
   invariability, invigorate, irritate, medullary sheath, mettle,
   moxie, nerve trunk, nerves, nervous system, nervousness, neuron,
   peripheral nervous system, pith, plexus, pluck, presumption,
   presumptuousness, prop, pushiness, reassure, refresh, reinforce,
   reinvigorate, reliability, resoluteness, restrengthen, rootedness,
   sand, sang-froid, sauce, secureness, security, self-assertion,
   self-assertiveness, self-expression, self-expressiveness,
   sensorium, sensory area, sensory cell, shore up, solar plexus,
   solidity, soundness, spinal cord, spirit, spunk, stability,
   stable equilibrium, stable state, stamina, staunchness,
   steadfastness, steadiness, steady nerves, steady state, steel,
   stiffen, stout heart, strengthen, stress, substantiality, support,
   sustain, synapse, temerity, temper, tenacity, tension,
   the heebie-jeebies, thoracolumbar nervous system, toughen,
   toughness, undeflectability, undergird, uniformity,
   unshakable nerves, unshakableness, upset, valor, white matter,
   will, worry