disappeared
v.v. to stop being visible or to go away suddenly so that you cannot find it. You use this when something is lost or when someone leaves a place without anyone noticing.
v. to cease to be visible or to pass out of existence. Intransitive — it does not take a direct object and cannot be used in the passive voice.
The sun disappeared behind the clouds.
I left my keys on the kitchen table, but they have completely disappeared.
The ancient civilization disappeared centuries ago, leaving behind only a few stone ruins and a language that no one can translate.
The verb is intransitive and never takes a direct object. It cannot be used in the passive voice (e.g., 'was disappeared' is incorrect in standard English).
The keys were disappeared.The keys disappeared.Disappear is intransitive; it cannot be used in the passive voice because there is no object to become the subject.