a nasty shock/surprise
There's a nasty smell in here.
He had a nasty cut above the eye.
She has a nasty habit of picking on people in meetings.
Don't be so nasty to your brother - he's four years younger than you!
In an emergency you could get out through a window, but it would be a nasty drop.
The situation could turn (= become) nasty at any moment.
She said some really nasty things about him.
I've got a nasty feeling that I forgot to tell Joe I couldn't come.