impounding vs drug bust

impounding and drug bust both are nouns.

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

As nouns, drug bust is a hyponym of impounding; that is, drug bust is a word with a more specific, narrower meaning than impounding:

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

Other hyponyms of impounding include drugs bust.

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