D defs.my
Entry 3 senses Webster, 1913

Exponent

/ĕk'-spōnˌ-ənt/ · Ex·po·nent · IPA /ɛkˈspoʊ.nənt/
01 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 repeat…
  1. 1.
    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(Alg.)
  2. 2.
    One who, or that which, stands as an index or representative; as, the leader of a party is the exponent of its principles.
  3. 3.
    one who explains, expounds, or interprets.
Phrases & compounds
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.