A sentence using "disappear" is, "When the magician made the rabbit disappear, the audience was left wondering how it happened." This sentence uses the primary meaning of disappear, which is to vanish from sight or to be seen no more.
Another meaning of disappear is to vanish suspiciously, such as in, "No one could figure out how Joni could just disappear without anyone knowing where she was for two hours." The word "disappear" is sometimes used as a substitute for kidnap or make go away. An example using this meaning is, "The political system is so corrupt that the politician with more money and power simply made his opponent disappear."