It's a bird! It's a plane! It's an albatross — in which case it's somewhere between the first two. An albatross is one of the largest flying birds in the world.
The word albatross comes from the Spanish and Portuguese word alcatraz meaning "pelican," but it's not just animals that this word describes. Think of the huge white prison on Alcatraz Island in San Francisco that hindered its inmates from going anywhere, reminding them daily of the guilt and burden of their crime — all feelings that are meant to be conjured by something that's an albatross in a person's life.