ersatz, adjective. Being a usually artificial and inferior substitute or imitation.
Etymology: direct from the German noun ersatz, substitute.
I recently purchased a jar of ersatzkaffee ("replacement coffee"). The term has been used for various coffee substitutes, but this one was just roasted barley. It looks and acts like instant coffee granules, and actually tastes pretty decent. It's caffeine free and supposedly loaded with health benefits.
The word has an unpleasant history, though. Prisoners during WWII were given ersatzbrot (replacement bread), made from inferior flours, chopped straw, sawdust, etc. Apparently, analysis of ersatz flour from Slavuta showed it to be 64% sawdust. Some actual flour needed to be added to it just to be able to make bread at all. Food made from this flour caused digestive diseases, inanition (exhaustion caused by lack of nourishment) and outright starvation.
My username (which is intended to rhyme with 'red', not 'reed') is a play on ersatz bread. If there can be anything playful about a word from a WWII prisoner camp.