etaoin shrdlu
noun
eta·oin shrd·lu
| \ ˈet|ēˌȯinˈshərdˌlü, ˈēt|, ˈāt|, |əˌȯi-, -n(ˌ)shərdˈlü\
plural -s
Definition of etaoin shrdlu
: a combination of letters set by running a finger down the first and then the second left-hand vertical banks of six keys of a Linotype machine to produce a temporary marking slug not intended to appear in the final printing