Meaning of etaoin shrdlu

et•a•oin shrd•lu

Pronunciation: (et'ē-oin" shûrd'l, -ō"in, ē'tē-), [key]
  1. the letters produced by running the finger down the first two vertical rows of keys at the left of the keyboard of a Linotype machine: used as a temporary marking slug or to indicate that an earlier mistake in the line necessitates resetting, but sometimes inadvertently cast and printed.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.