The Collaborative International Dictionary of English v.0.48:

Reluctance \Re*luc"tance\ (r?-l?k"tans), Reluctancy
\Re*luc"tan*cy\ (-tan-s?), n. [See Reluctant.]
   1. The state or quality of being reluctant; repugnance;
      aversion of mind; unwillingness; -- often followed by an
      infinitive, or by to and a noun, formerly sometimes by
      against. "Tempering the severity of his looks with a
      reluctance to the action." --Dryden.

   Syn: Syn. See Dislike.
        [1913 Webster]

              He had some reluctance to obey the summons. --Sir
                                                  W. Scott.
        [1913 Webster]

              Bear witness, Heaven, with what reluctancy
              Her helpless innocence I doom to die. --Dryden.
        [1913 Webster]

   2. (Elec.) Magnetic resistance, being equal to the ratio of
      magnetomotive force to magnetic flux.
      [Webster 1913 Suppl.]

WordNet (r) 3.0 (2006):

reluctance
    n 1: (physics) opposition to magnetic flux (analogous to
         electric resistance)
    2: a certain degree of unwillingness; "a reluctance to commit
       himself"; "his hesitancy revealed his basic indisposition";
       "after some hesitation he agreed" [syn: reluctance,
       hesitancy, hesitation, disinclination, indisposition]