roar

Concise Oxford English Dictionary © 2008 Oxford University Press:
roar/rɔː(r)/

▶noun a full, deep, prolonged sound as made by a lion, natural force, or engine.

■ a loud, deep sound uttered by a person, especially as an expression of pain, anger, or great amusement.

▶verb

• 1 make or utter a roar.

  ■ express in a roar.

  ■ laugh loudly.

  ■ (of a horse) make a loud noise in breathing as a symptom of disease of the larynx.

• 2 (of a vehicle) move with a roar at high speed.

  ■ act or happen fast and decisively.

– derivatives
roarer noun.

– origin OE rārian (v.), imitative of a deep prolonged cry, of W. Gmc origin.