Here Rosten explains the tradition amongst Yiddish speakers of mocking a person or an object by attaching a sh or shm to the beginning of a word. For example 'Who said that? Charley? Charley-shmarley, what does he know?'
Taken from: The Joys of Yiddish Author / Creator: Rosten, Leo Publisher: McGraw-Hill Book Co, New York Date: 1968 Copyright: © The British Library Board Shelfmark: LEX.155
The Joys of Yiddish - Title Page
The Joys of Yiddish - Chutzpa
The Joys of Yiddish - Words-Shmords
The Joys of Yiddish - Shmooz and Shmuck