Use the noun bugaboo to describe something that causes worry, like the bugaboo of having three tests on the same day at school.

Bugaboo is also another name for the creature known as the bogeyman, an imaginary monster that children believe will hurt them or even take them away if they don't behave. Some usage experts trace bugaboo to Scotland, where the now-obsolete word bogill meant "goblin, bugbear." A bugbear, in the 1580 coining of the word, was a demon that looked like a bear and ate small children.

Definitions of bugaboo

n an imaginary monster used to frighten children

bogeyman, booger, boogeyman, bugbear
Type of:
an imaginary creature usually having various human and animal parts

n a source of concern

“the old bugaboo of inflation still bothers them”
Type of:
concern, headache, vexation, worry
something or someone that causes anxiety; a source of unhappiness

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