A disappearance is when someone or something vanishes and cannot be found. When a person goes missing, their sudden absence and unknown whereabouts create a disappearance. When your favorite pen seems to vanish from your desk, that's a small disappearance. When a species dies out completely, scientists call it a disappearance from Earth.

The word carries a sense of mystery and concern because disappearances happen without clear explanation. If you knew your pen rolled under the couch, it wouldn't really be a disappearance anymore: it would just be lost. True disappearances puzzle us because we don't know what happened or where something went.

History records famous disappearances that remain unsolved: the colony at Roanoke that vanished in the 1580s, Amelia Earhart's plane over the Pacific Ocean, and stories about ships and aircraft in the Bermuda Triangle. These mysteries capture our imagination because the lack of answers leaves us wondering.

The word can also describe something fading away gradually. The disappearance of fireflies in a neighborhood might happen over several years as habitats change. The gradual disappearance of a tradition occurs when fewer people practice it with each generation. In magic shows, a magician might perform an impressive disappearance, making something seem to vanish instantly, though of course it's really just a clever illusion.