interjection / noun / verb
vroom
VROOM/vrˈum/
The roaring sound of a rapidly revving engine.
Vroom! The grandfather imitates an engine as he accelerates the toy car.

Etymology
The word was coined to echo a motor engine revving, so saying it directly imitates the noise it stands for.
In context
And vroom vroom vroom [music] goes the airplane. Vroom vroom vroom.
More examples
- "Vroom, vroom!" she says, pretending to drive a race car.
- We hear the vroom of an engine outside.
- A sports car vrooms past us on the highway.
Forms
vroom · vrooms · vroomed · vrooming