The disappearance or vanishing of something; loss or wearing away (can refer to physical disappearance, data loss, fading, memory loss, etc.).
大事なデータがサーバーの故障で消失した。
Important data was lost due to a server failure.
古い建物は年月とともに消失してしまった。
The old building eventually disappeared over the years.
薬の副作用で一時的に記憶の消失が起きることがある。
Side effects of the drug can sometimes cause temporary memory loss.