bugbear

{ } n. [ See Bug. ] Something frightful, as a specter; anything imaginary that causes needless fright; something used to excite needless fear; also, something really dangerous, or an imaginary monster, used to frighten children, etc. “Bugaboos to fright ye.” Lloyd. [ 1913 Webster ]

But, to the world no bugbear is so great
As want of figure and a small estate. Pope. [ 1913 Webster ]

The bugaboo of the liberals is the church pray. S. B. Griffin. [ 1913 Webster ]

The great bugaboo of the birds is the owl. J. Burroughs. [ 1913 Webster ]

2. a source of concern; as, the old bugaboo of inflation still bothers them. [ WordNet 1.5 ]

Syn. -- Hobgoblin; goblin; specter; ogre; scarecrow; bogeyman; boogeyman; booger. [ 1913 Webster ]