replacement vs ersatz

replacement and ersatz both are nouns.

Word	Noun	Adjective	Verb	Adverb
replacement	Yes	No	No	No
ersatz	Yes	Yes	No	No

As nouns, ersatz is a hyponym of replacement; that is, ersatz is a word with a more specific, narrower meaning than replacement:

Other hyponyms of replacement include successor, succedaneum, poor relation.

replacement (noun)	ersatz (noun)
the act of furnishing an equivalent person or thing in the place of another	an artificial or inferior substitute or imitation
a person or thing that takes or can take the place of another
an event in which one thing is substituted for another
a person who follows next in order
someone who takes the place of another person
filling again by supplying what has been used up

replacement (adjective)	ersatz (adjective)
	artificial and inferior