exponential
adj.describing a rate of change that becomes faster and faster over time. You use it when a small increase quickly turns into a very large one.
adj.relating to an increase that becomes more rapid in proportion to the growing total number or size. Often describes growth patterns in mathematics, biology, or finance.
“The company saw exponential growth in its first year.”
“The virus spread at an exponential rate because each infected person passed it to several others.”
“While linear progress is easy to predict, exponential shifts in technology often catch society off guard because the most dramatic changes occur in the final stages of the cycle.”
Commonly modifies nouns like 'growth', 'increase', or 'rise'.
In general English, the word is almost always used as an adjective to modify a noun, not as a noun itself.
“Rojas said the influx had led to an exponential increase in sexual assault, and many victims did not file a report, either out of fear of because of their "current situation in Ceuta".”
“The Golden Triangle – the remote, jungle-covered border region where Thailand, Myanmar, and the Lao People’s Democratic Republic meet – has seen an exponential surge in the illicit manufacture and trafficking of synthetic drugs.”
From exponent + -ial.
Etymology adapted from Wiktionary, available under CC BY-SA 4.0.