(n.) A contrivance consisting of a slat of wood tied to the end of a thong or string, with which the slat is whirled so as to cause an intermittent roaring noise. It is used as a toy, and among some races in certain religious rites.
BULL-ROARER
Meaning of BULL-ROARER in English
Webster's English dictionary. Английский словарь Webster. 2012