Bugbear (noun)

1. A source of annoyance or fear.
2. An object of unfounded or exaggerated fear.

Origin:

From the middle english word "buggebere" meaning "a goblin or devil".

Examples:

1. Public speaking is a bugbear for many people.
2. The bugbear of his childhood was the dark.
3. The bugbear of the project was the tight deadline.
4. Taxes are a bugbear for many businesses.
5. The bugbear of the company was the unreliable supplier.