CHANGELING n. 2 definitions
One who, or that which, is left or taken in the place of another, as a child exchanged by fairies. Such, men do changelings call, so changed by fairies' theft. Spenser. The changeling [a substituted writing] never known. Shak.
CHECK n. 2 definitions
A mark, certificate, or token, by which, errors may be prevented, or a thing or person may be identified; as, checks placed against items in an account; a check given for baggage; a return check on a railroad.