Webster's Revised Unabridged Dictionary · 1913

Changeling

Changeling , noun

[Change + -ling.]

1.
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. — Shakespeare
2.
A simpleton; an idiot. — Macaulay
Changelings and fools of heaven, and thence shut out.
Wildly we roam in discontent about.
3.
One apt to change; a waverer.
Fickle changelings. — Shakespeare

Changeling , adjective

1.
Taken or left in place of another; changed.
A little changeling boy. — Shakespeare
2.
Given to change; inconstant. [Obsolete]
Some are so studiously changeling. — Boyle