The massive Oxford English Dictionary is, practically speaking, the official and exhaustive guide to the words of the English language. John Simpson, the Chief Editor, is retiring after 37 years with the project. He's spent decades tracking down the origins of different words. Simpson wrote in BBC News about his favorite word origins, such as etaoin shrdlu:
Etaoin shrdlu is an expression well known to newspaper compositors and little-known to readers.
It comes from the same stable as Anthony Burgess's Homage to Qwert Yuiop. Qwertyuiop is what you find on a computer screen (or, in the old days, on a typewriter) if you run your fingers along the top row of letters on a keyboard.
Etaoin shrdlu is the equivalent sequence of letters that an old-style Linotype printing machine operator would have put out by running his (or her) finger down the first two (leftmost) columns of Linotype keys.
But etaoin shrdlu had a purpose. The Linotype operator would hit these keys intentionally to signal that an error had been made and the preceding line should be removed from the type before it was printed.
Sometimes the type-setters and proofreaders were asleep and missed this alarm bell.
At the link, you can read about the origins of the words pom, pal, nacho and more.
Link -Thanks, Virginia!