From the Glossary of The Wheel of Time

Saying the true name of the Dark One (Shai'tan) draws his attention, inevitably bringing ill fortune at best, disaster at worst. For that reason many euphemisms are used, among them the Dark One, Father of Lies, Sightblinder, Lord of the Grave, Shepherd of the Night, Heartsbane, Heartfang, Grassburner, and Leaf-Blighter. Someone who seems to be inviting ill fortune is often said to be "naming the Dark One."