Webster’s Revised Unabridged Dictionary · 1913
Exponential
Ex′po·nen′tial (ĕks′pō·nĕn′shal), a. [Cf. F. exponentiel.] Pertaining to exponents; involving variable exponents; as, an exponential expression; exponential calculus; an exponential function.
Exponential curve, a curve whose nature is defined by means of an exponential equation. — Exponential equation, an equation which contains an exponential quantity, or in which the unknown quantity enters as an exponent. — Exponential quantity (Math.), a quantity whose exponent is unknown or variable, as ax. — Exponential series, a series derived from the development of exponential equations or quantities.