impoundment vs poundage

impoundment and poundage both are nouns.

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

As nouns, impoundment and poundage are synonyms defined as:

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

Other synonyms of impoundment include impounding, internment.

impoundment (noun)	poundage (noun)
placing private property in the custody of an officer of the law	placing private property in the custody of an officer of the law
	weight expressed in pounds
	a fee charged for the recovery of impounded animals
	a charge based on weight measured in pounds