changeling

/ˈtʃeɪn(d)ʒlɪŋ/noun
High SchoolNot in standard dictionaries
1

In pre-modern European folklore: an infant of a magical creature that was secretly exchanged for a human infant. In British, Irish and Scandinavian mythology the exchanged infants were thought to be those of fairies, sprites or trolls; in other places, they were ascribed to demons, devils, or witches.

2

A person or object (especially when regarded as inferior) secretly exchanged for something else.

3

An infant secretly exchanged with another infant deliberately or by mistake; a swapling.

4

An organism which can change shape to mimic others; a shape-shifter.

5

A person apt to change their loyalty or thinking; a waverer.

6

An idiot, a simpleton.

#archaic#informal#obsolete#rare