1. A bugaboo.
2. A fearsome imaginary creature, especially one evoked to frighten children.

[Obsolete bug, hobgoblin (from Middle English bugge , perhaps from Welsh bwg) + BEAR².]

The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.