▪ an instance or fact of someone going missing or (in coded political language) being killed: "the police were investigating her disappearance"SimilarlosstheftrobberystealingthievingrobbingpilferingpilferagepurloiningOppositerecovery
▪ the process or fact of something ceasing to exist or be in use:"the disappearance of grammar schools"Similardying outdyingdeathextinctioncoming to an endendingpassing awaypassing into oblivionexpiryvanishingperishingwithering awaypetering outfizzling out