exactly

Exactly is an adverb used to indicate precision or exactness. It signals that an assertion, amount, or description is without deviation from a stated standard or value, and that no approximation is implied.

In mathematics and measurement, exactly denotes equality with a stated value. For example, "The answer is exactly 42" asserts perfect agreement with the value 42 and contrasts with "approximately" or "about." In logic and counting, it is tied to exact results rather than rounded or estimated ones.

In ordinary speech, exactly can function as an intensifier or as an interjection meaning agreement or affirmation, as in "Exactly!" or "That's exactly what I meant." It can emphasize the precision of a statement or timing.

It derives from the adjective exact, which in turn comes from Latin exactus "done with accuracy," via Old French, and entered English in the early modern period.

Related concepts include precision, exactness, and exact arithmetic. In computing, exact arithmetic uses rational or integer representations to avoid rounding errors, in contrast to floating-point or approximate methods.