retard vs changeling

retard and changeling both are nouns.

Word	Noun	Adjective	Verb	Adverb
retard	Yes	No	Yes	No
changeling	Yes	No	No	No

As nouns, retard and changeling are synonyms defined as:

Other synonyms of retard include cretin, half-wit, idiot, imbecile, moron.

retard (noun)	changeling (noun)
a person of subnormal intelligence	a child secretly exchanged for another in infancy
	a person of subnormal intelligence

retard (verb)	changeling (verb)
lose velocity; move more slowly
cause to move more slowly or operate at a slower rate
slow the growth or development of
be delayed