Exponential

How to spell exponential

11 letters · 4 syllables

How to pronounce exponential

Say the part in capitals loudest.

What does exponential mean?

1. adjectiveIncreasing or decreasing at a rate that itself accelerates, becoming rapidly larger or smaller over time.
2. adjectiveRelating to a mathematical expression in which a variable appears as an exponent or power.

Exponential in a sentence

• The start-up reported exponential growth in its user numbers last quarter.

• The teacher asked the class to plot an exponential function on the graph.

• Compound interest produces exponential returns over many decades.

• Radioactive decay is modelled with an exponential equation.

Where does exponential come from?

Language of origin: Latin

This word traces back to the Latin verb ponere, meaning 'to place' or 'to put', combined with the prefix ex-, meaning 'out'. The compound exponere literally meant 'to put out' or 'to set forth', and from its participle came the mathematical term 'exponent', the small raised number that sets forth how many times a base is multiplied by itself. By the seventeenth century mathematicians had formed 'exponential' to describe quantities that grow according to such a power, where the variable sits in the exponent itself. From there the word spread into everyday speech, where 'exponential growth' now loosely means any increase that gets dramatically faster over time. The same ponere root quietly underlies many familiar words, including 'component', 'opponent', and 'postpone', which is a useful reminder that the tricky middle is spelled p-o-n-e-n, not p-o-n-a-n.

How the word is built

• ex- (out)
• ponent (from Latin ponere: to place/put)
• -ial (adjective suffix)