disappearance       
noun [ C or U ] uk/ˌdɪs.əˈpɪə.rəns/ us/ˌdɪs.əˈpɪr.əns/
B2 消失;失踪
the fact of someone or something disappearing
  A man was being questioned in connection with her disappearance. 一个与她失踪有关的人正在接受盘问。 
 - More examples
 - An investigation has been under way for several days into the disappearance of a 13-year-old boy.
 - Her disappearance was reported to the police department's Missing Persons Bureau.
 - After ten years her mystifying disappearance was still unexplained.
 - The disappearance of the ship, on a routine mission in 1925, has never been explained.
 - Many viewers are furious about the programme's sudden disappearance from the schedules.