A shipwrecked sailor.

“Robinson Crusoe was a famous fictional castaway.”

A discarded person or thing.

“This old coat was a castaway in someone's trash.”

An outcast; someone cast out of a group or society.

“These homeless people are society's castaways.”

Cast adrift or ashore; marooned.

“After the mutiny, the castaway ship's officers suffered a month at sea in the lifeboat.”

Shipwrecked.

“The storm left them castaway on an uninhabited island.”

Cast out; rejected or excluded from a group.