I was at a party recently and a woman was describing an evening gown she bought for an upcoming event. I thought I was following along pretty well until I heard her say "air socks". Hmmm....Were air socks a new fashion trend I was unaware of? It seemed a little strange in the context of formal wear, though, so I asked her what she said by repeating "Air socks?" "Ersatz", she confirmed adding helpfully, "it's German." "Oh, you said e-r-s-a-t-z", I thought you said "a-i-r s-o-c-k-s". As you can imagine, that was the end of our fashion conversation.
Tonight I googled "ersatz" and discovered the word means "substituting for or inferior in quality to". I guess ersatz chiffon makes a lot more sense than air socks chiffon.