Inverted; turned so that the top is at the bottom.

“The pattern resembled an upside down letter W.”

In great disorder.

Owing more money for something than it is worth; having negative equity.

“He's upside down on his mortgage.”

Inverted, so that the top is now at the bottom.

“The Union flag was flying upside down, a sign of danger.”

In great disorder.

“The thief had turned the room upside down.”