There's nothing spookier than an abandoned house that's still full of dusty, decaying furniture. When something is abandoned, it's been cast off or deserted.
The adjective abandoned describes something that's been given up or discarded. You can use it to talk about a kitten abandoned at an animal shelter, an old car abandoned by the side of the road, or a person's dreams of becoming an opera singer abandoned when they had kids. It comes from the French phrase mettre a bandon, "put someone under another's control."