The lovely German word ersatz is both an adjective meaning “serving as a substitute” and a noun meaning “an artificial or inferior substitute”.
In German, the word literally means “replacement” or “substitute”. According to Wikipedia:
The term ersatz probably gained international attention during World War I, when Allied fleets cut off all sea transports to Germany, forcing Germany to develop substitutes for products like chemical compounds and provisions.
But according to the Online Etymology Dictionary, the term was used to mean “units of the army reserve”.
Regardless of its previous meanings, today ersatz is a good old American word still used to add a little flare when “substitute” doesn’t sound interesting enough. For some usage examples, search for it on Google News. My favorite example mentions “Alec Baldwin