drug bust vs impoundment

drug bust and impoundment both are nouns.

Word	Noun	Adjective	Verb	Adverb
drug bust	Yes	No	No	No
impoundment	Yes	No	No	No

As nouns, impoundment is a hypernym of drug bust; that is, impoundment is a word with a broader meaning than drug bust:

drug bust: seizure of illegal drugs by the police
impoundment: placing private property in the custody of an officer of the law

Other hypernyms of drug bust include impounding, internment, poundage.

drug bust (noun)	impoundment (noun)
seizure of illegal drugs by the police	placing private property in the custody of an officer of the law