incredibly

Incredibly is an English adverb used to indicate a very high degree or extent. It typically modifies adjectives, verbs, or other adverbs, as in incredibly fast or incredibly well. The word signals emphasis or astonishment and is widely used across spoken and written English.

Usage notes: incredibly is a common intensifier but can seem informal or hyperbolic in formal writing. In many contexts, alternatives such as extremely, extraordinarily, or remarkably may be preferable for precise or neutral tone. Overuse can dilute impact or sound cliché.

Etymology: incredibly derives from the adjective incredible, formed in English by adding the -ly adverbial suffix. The adjective itself comes from Latin incredibilis “not credible,” from incredere “to lack belief.” The adverb has been part of English since the Early Modern period, with usage expanding in later centuries.

See also: incredible, incredulous, unbelievable.