internment vs impoundment

internment and impoundment both are nouns.

Word	Noun	Adjective	Verb	Adverb
internment	Yes	No	No	No
impoundment	Yes	No	No	No

As nouns, internment and impoundment are synonyms defined as:

internment and impoundment: placing private property in the custody of an officer of the law

Other synonyms of internment include impounding, poundage.

internment (noun)	impoundment (noun)
the act of confining someone in a prison (or as if in a prison)	placing private property in the custody of an officer of the law
placing private property in the custody of an officer of the law
confinement during wartime