Webster’s Revised Unabridged Dictionary · 1913
Bugaboo
Bug′a·boo′ (·ȧ·bo͞o′), Bug′bear′, n. [See Bug.] Something frightful, as a specter; anything imaginary that causes needless fright; something used to excite needless fear; also, something really dangerous, used to frighten children, etc. "Bugaboos to fright ye." Lloyd.
But, to the world no bugbear is so great As want of figure and a small estate. Pope.
The bugaboo of the liberals is the church pray. S. B. Griffin.
The great bugaboo of the birds is the owl. J. Burroughs.
Syn. — Hobgoblin; goblin; specter; ogre; scarecrow.