1670s, "explosion accompanied by loud sound," from French détonation, from Medieval Latin detonationem (nominative detonatio), from Latin detonare "to thunder down, to release one's thunder, roar out," from de- "down" (see de-) + tonare "to thunder" (see thunder (n.)). Sense of "act of causing to explode" (mid-18c.) developed in French.[detonation etymology, detonation origin, 英语词源]