Hyperbole is a formal word for what is more usually called exaggeration. "I've told you a thousand times", an exasperated parent may say. It is unlikely to be literally true. Therefore it is figurative language: it is a Figure of Speech. "I've told you tons of times" is doubly figurative: it is a hyperbole and a metaphor.
Hyperbole is a transliteration of the Greek word ὑπερβολή (huperbolē, 'throwing beyond others', 'overshooting', 'excess', and 'hyperbole'). It is pronounced with emphasis on the second syllable: hy-PER-bul-ee.