Source : Webster's Revised Unabridged Dictionary (1913)

Exponent \Ex*po"nent\, n. [L. exponens, -entis, p. pr. of
   exponere to put out, set forth, expose. See {Expound}.]
   1. (Alg.) A number, letter, or any quantity written on the
      right hand of and above another quantity, and denoting how
      many times the latter is repeated as a factor to produce
      the power indicated;

   Note: thus a^{2} denotes the second power, and a^{n} the xth
         power, of a (2 and x being the exponents). A fractional
         exponent, or index, is used to denote the root of a
         quantity. Thus, a^{1/3} denotes the third or cube root
         of a.

   2. One who, or that which, stands as an index or
      representative; as, the leader of a party is the exponent
      of its principles.

   {Exponent of a ratio}, the quotient arising when the
      antecedent is divided by the consequent; thus, 6 is the
      exponent of the ratio of 30 to 5. [R.]

Source : WordNet®

exponent
     n 1: a person who pleads for a cause or propounds an idea [syn: {advocate},
           {advocator}, {proponent}]
     2: someone who expounds and interprets or explains
     3: a mathematical notation indicating the number of times a
        quantity is multiplied by itself [syn: {power}, {index}]

Source : Free On-Line Dictionary of Computing

exponent
     
         (Or "characteristic") The part of a
        {floating-point} number specifying the power of ten by which
        the {mantissa} should be multiplied.  In the common notation,
        e.g. 3.1E8, the exponent is 8.
     
        (1995-02-27)