Vroom

Vroom (also spelt varoom) is an onomatopoeia that represents the sound of an engine revving up. It also describes the act of purposefully operating a motor vehicle at high speeds so as to create loud engine noises. The word is a common early childhood sound, and is used in speech therapy techniques. It is also an example of a cross-linguistic onom
Found on http://en.wikipedia.org/wiki/Vroom

vroom

[v] - make a loud, roaring sound, as of a car engine, while moving
Found on http://www.webdictionary.co.uk/definition.php?query=vroom

vroom

noun the roaring sound made by a motor that is running at high speed
Found on http://wordnetweb.princeton.edu/perl/webwn?s=vroom
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