exponent

n. 1 person who promotes an idea etc. 2 practitioner of an activity, profession, etc. 3 person who explains or interprets something. 4 type or representative. 5 raised symbol beside a numeral indicating how many of the number are to be multiplied together (e.g. 23 = 2 x 2 x 2). [latin expono *expound]

n. 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