early 15c., disaperen, "cease to be visible, vanish from sight, be no longer seen," from dis- "do the opposite of" + appear. Earlier was disparish (early 15c.), from French disparaiss-, stem of desapparoistre (Modern French disparaître).
Transitive sense, "cause to disappear," is from 1897 in chemistry; by 1948 of inconvenient persons. Related: Disappeared; disappearing; disappears. Slang disappearing act "fact of absconding, action of getting away," is attested by 1884, probably originally a reference to magic shows.