D defs.my
Entry 2 senses Webster, 1913

Bugaboo

/bŭg'-əb-o͞oˌ/ · Bug·a·boo · IPA /ˈbʌɡəbuː/
01 n. Something frightful, as a specter; anything imaginary that causes needless fright; something used to excite needless fear; also, something …
  1. 1.
    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.
    “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.
  2. 2.
    a source of concern; as, the old bugaboo of inflation still bothers them.