Learner's definition of VROOM
[count] informal
: the sound made by the engine of a car, truck, etc., when it is running very fast（汽车、卡车等高速行驶时发出的）呜呜声 —
often used as an interjection to imitate the sound of an engine常用作感叹词，模仿引擎声音
— vroom
verb vrooms; vroomed; vrooming [no object]