1. the act or fact of becoming impossible to see or find
2. the state of being lost or missing, especially when unexplained

Examples

• The magician’s disappearance from the stage amazed the audience.
• Police are investigating the mysterious disappearance of the hiker.
• The disappearance of the sun behind the clouds made it suddenly cold.
• Her sudden disappearance from school worried her friends.
• The disappearance of many species is a serious environmental concern.
• The witness reported the car’s disappearance around the corner.
• Scientists study the gradual disappearance of glaciers due to climate change.