stoppage vs impediment

stoppage and impediment both are nouns.

Word	Noun	Adjective	Verb	Adverb
stoppage	Yes	No	No	No
impediment	Yes	No	No	No

As nouns, impediment is a hypernym of stoppage; that is, impediment is a word with a broader meaning than stoppage:

Other hypernyms of stoppage include impedimenta, obstructer, obstruction, obstructor.

stoppage (noun)	impediment (noun)
the act of stopping something	any structure that makes progress difficult
an obstruction in a pipe or tube	something immaterial that interferes with or delays action or progress
the state of inactivity following an interruption