exponential
Entry from World dictionary
Pronunciation:/ˌɛkspəˈnɛnʃ(ə)l/
adjective
- 1 (of an increase) becoming more and more rapid:the social security budget was rising at an exponential rate
- 2 Mathematicsof or expressed by a mathematical exponent:an exponential curve

Derivatives
exponentially
adverb

Origin:
early 18th century: from French exponentiel, from Latin exponere 'put out' (see expound)