Definition of bull-roarer:
(n) :
An adult male of domesticated cattle or oxen.
(n) :
Specifically, one that is uncastrated.
(n) :
(loosely) Any bovine of an aggressive or long-horned breed regardless of age and sex.
(n) :
A male of domesticated cattle or oxen of any age.
(n) :
Any adult male bovine.
(n) :
An adult male of certain large mammals, such as whales, elephants, camels and seals.