exponential

American  

[ek-spoh-nen-shuhl, -spuh-] / ˌɛk spoʊˈnɛn ʃəl, -spə- /

adjective

1. of or relating to an exponent or exponents.

2. Mathematics.

   1. of or relating to the constant e.

   2. (of an equation) having one or more unknown variables in one or more exponents.

3. rising or expanding at a steady, rapid rate.

   a city experiencing exponential growth.

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noun

1. Mathematics.

   1. the constant e raised to the power equal to a given expression, as e 3 x, which is the exponential of 3 x.

   2. any positive constant raised to a power.

exponential British  

/ ˌɛkspəʊˈnɛnʃəl /

adjective

1. maths (of a function, curve, series, or equation) of, containing, or involving one or more numbers or quantities raised to an exponent, esp e x

2.  exp.  maths raised to the power of e, the base of natural logarithms

3. of or involving an exponent or exponents

4. informal very rapid

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noun

1. maths an exponential function, etc

exponential Scientific  

/ ĕk′spə-nĕn′shəl /

1. Relating to a mathematical expression containing one or more exponents.

2. ◆ Something is said to increase or decrease exponentially if its rate of change must be expressed using exponents. A graph of such a rate would appear not as a straight line, but as a curve that continually becomes steeper or shallower.

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Other Word Forms

• exponentially adverb
• nonexponential adjective

Etymology

Origin of exponential

First recorded in 1695–1705; exponent + -ial

Explanation

Exponential describes a very rapid increase. An exponential rise in the number of first graders with head lice might be a result of all the hat sharing that's gone on lately. Exponential is also a mathematical term, meaning "involving an exponent." When you raise a number to the tenth power, for example, that's an exponential increase in that number. When your next door neighbor describes the exponential growth of her rose bushes or the exponential increase in members of her book group, she means that there's been a sharp, fast expansion of both things.

Example Sentences

This week the stock reclaimed both its 50-day and 200-day simple moving averages and it is well above its 21-day exponential moving average.

From Barron's • Apr. 21, 2026

With weekly volume point of control of US$0.7098 hovering between 10- and 20-day exponential moving averages, US$0.7100 appears to be a reasonable near-term target for Australian dollar bears, he says.

From The Wall Street Journal • Apr. 20, 2026

"We're on the flat part of the exponential curve."

From BBC • Apr. 13, 2026

It is rare in its group because it never undercut its 200 day simple moving average, and is trading right at its 21 day exponential moving average, which signals strong momentum.

From Barron's • Mar. 23, 2026

The universe would have started off with a period of exponential or “inflationary” expansion in which it would have increased its size by a very large factor.

From "A Brief History of Time: And Other Essays" by Stephen Hawking