How did the letter Z come to be associated with sleeping/snoring?"How and when did the letter Z become to be associated with sleeping?" First of all, zzzz (or z-z-z-z) is sound of snoring, from at least 1918. (Sometimes "a tiny saw cutting through a log" [1948] would be used, and both the snore and saw would make the same z-z-z-z sound.) Over time, this became associated with sleep in general, but most comic reference books (e.g. 2006's KA-BOOM! A Dictionary of
