worrywart

noun
UK /ˈwʌriwɔːt/
US /ˈwɜːriwɔːrt/

A worrywart is a person who worries a lot about small things.

My brother is such a worrywart that he checks his homework five times.


OTHER MEANINGS

2. Someone who always expects something bad to happen.

Don't be a worrywart; the rain will stop before the game.

3. A person who fusses over details others find unimportant.

Our worrywart neighbor called twice to ask if we locked the gate.

4. A playful name for a friend who panics easily.

Relax, worrywart, the test isn't until Friday!