Hyperbole

Hy·per′bo·le (·bō·l̇), n. [L., fr. Gr?, prop., an overshooting, excess, fr. Gr. ὑπερβάλλειν to throw over or beyond; ὑπέρ over + βάλλειν to throw. See Hyper-, Parable, and cf. Hyperbola.] (Rhet.) A figure of speech in which the expression is an evident exaggeration of the meaning intended to be conveyed, or by which things are represented as much greater or less, better or worse, than they really are; a statement exaggerated fancifully, through excitement, or for effect.

Our common forms of compliment are almost all of them extravagant hyperboles. Blair.

Somebody has said of the boldest figure in rhetoric, the hyperbole, that it lies without deceiving. Macaulay.