The Collaborative International Dictionary of English v.0.48:

Resistance \Re*sist"ance\ (-ans), n. [F. r['e]sistance, LL.
   resistentia, fr. resistens, -entis, p. pr. See Resist.]
   1. The act of resisting; opposition, passive or active.
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            When King Demetrius saw that . . . no resistance was
            made against him, he sent away all his forces. --1.
                                                  Macc. xi. 38.
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   2. (Physics) The quality of not yielding to force or external
      pressure; that power of a body which acts in opposition to
      the impulse or pressure of another, or which prevents the
      effect of another power; as, the resistance of the air to
      a body passing through it; the resistance of a target to
      projectiles.
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   3. A means or method of resisting; that which resists.
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            Unfold to us some warlike resistance. --Shak.
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   4. (Elec.) A certain hindrance or opposition to the passage
      of an electrical current or discharge offered by
      conducting bodies. It bears an inverse relation to the
      conductivity, -- good conductors having a small
      resistance, while poor conductors or insulators have a
      very high resistance. The unit of resistance is the ohm.
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   Resistance box (Elec.), a rheostat consisting of a box or
      case containing a number of resistance coils of standard
      values so arranged that they can be combined in various
      ways to afford more or less resistance.

   Resistance coil (Elec.), a coil of wire introduced into an
      electric circuit to increase the resistance.

   Solid of least resistance (Mech.), a solid of such a form
      as to experience, in moving in a fluid, less resistance
      than any other solid having the same base, height, and
      volume.
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WordNet (r) 3.0 (2006):

resistance
    n 1: the action of opposing something that you disapprove or
         disagree with; "he encountered a general feeling of
         resistance from many citizens"; "despite opposition from
         the newspapers he went ahead" [syn: resistance,
         opposition]
    2: any mechanical force that tends to retard or oppose motion
    3: a material's opposition to the flow of electric current;
       measured in ohms [syn: electric resistance, electrical
       resistance, impedance, resistance, resistivity, ohmic
       resistance]
    4: the military action of resisting the enemy's advance; "the
       enemy offered little resistance"
    5: (medicine) the condition in which an organism can resist
       disease [syn: immunity, resistance]
    6: the capacity of an organism to defend itself against harmful
       environmental agents; "these trees are widely planted because
       of their resistance to salt and smog"
    7: a secret group organized to overthrow a government or
       occupation force [syn: underground, resistance]
    8: the degree of unresponsiveness of a disease-causing
       microorganism to antibiotics or other drugs (as in
       penicillin-resistant bacteria)
    9: (psychiatry) an unwillingness to bring repressed feelings
       into conscious awareness
    10: an electrical device that resists the flow of electrical
        current [syn: resistor, resistance]
    11: group action in opposition to those in power