jounce
To bounce or shake roughly, in a hard, bumpy way.
To jounce means to bounce or jolt roughly, like when a car hits a pothole and everyone inside gets thrown up and down in their seats. The word captures that uncomfortable, bumpy kind of movement where things shake around more violently than a gentle bounce.
When a wagon jounces down a rocky road, passengers feel every bump rattling through their bones. A box in the back of a truck might jounce around as the vehicle drives over rough terrain, making everything inside clatter and shift. You might jounce along on a bicycle with flat tires, feeling each crack in the sidewalk.
The word is stronger than “bounce,” which can sound fun and playful. Jouncing feels harsh and jarring. If you're carrying a cup of juice while someone jounces you on their shoulders, you'll probably spill it.
You can also use jounce as a noun: “That last jounce over the speed bump knocked my book off my lap.” The word perfectly captures that sudden, rough movement that makes you glad when the ride finally smooths out.