Historical clue formulations

• Language from which we get bupkis and shtick — 2023-08-30
• Whence the words "nosh" and "tush" — 2019-12-21
• Source of the six longest Across answers in this puzzle — 2018-09-19
• Bagel source? — 2013-11-29
• Singer's tongue — 2013-05-03