means A sharp, fast-moving front of pressure—through air, water, rock, or anything else—where conditions change almost instantly, as from an explosion, an earthquake, or an object moving faster than sound; also used figuratively for a jolt that ripples outward from a sudden event.

from A transparent English compound of "shock" and "wave." "Shock," meaning a violent collision or jolt, came into English in the 16th century, probably from French "choc" / "choquer," of uncertain earlier origin. "Wave," for the rolling motion of water, traces back to Old English "wafian," to wave or fluctuate. Bolted together, they name the thing precisely: a jolt that travels like a wave—a term that earned its keep with the rise of physics, ballistics, and aviation, and then spread outward into politics, markets, and gossip, wherever one sudden event sets everything else trembling.