Disappearance Common

the act of leaving secretly or without explanation

"After he suddenly vanished from his apartment last night, everyone assumed a mysterious disappearance had occurred."

the event of passing out of sight

"The sudden disappearance of the cat behind the sofa had us wondering if it was hiding or actually gone."

gradually ceasing to be visible

"As the sun set behind the hills, the snow-capped peak began its slow disappearance into the twilight haze."

ceasing to exist

"he regretted the disappearance of Greek from school curricula"

"what was responsible for the disappearance of the rainforest?"

"the disappearance of resistance at very low temperatures"

The action of disappearing or vanishing.

"The disappearance of the rare blue whale has left marine biologists searching for answers."