As New Year's approaches, I wonder what words and concepts familiar to an American born around 1950 have disappeared to the point that they puzzle most of those under 60 years of age?
Here is a list complied with help from my contemporaries and from younger folk. Further suggestions are welcome.

(December 31, 2021)
Jan. 9, 2022 update: For many more vanished American words proposed by readers, click here.