Sandman n. : A mythical person who makes children sleepy, so that they rub their eyes as if there were sand in them.

Example:
How do you play the Sandman sleepover game?

Taxonomy
The Sandman, Sandman, Neil Gaiman, comics, Morpheus, DC Comics, Death, Vertigo, Illustrator, characters, Dream, short stories, The Doll's House, comic books, Preludes and Nocturnes, The Absolute, Season of Mists, collections.

Defination from the web:
Sandman is an epic comic book series written by Neil Gaiman and published in the United States by the DC Comics imprint Vertigo. ... The Sandman was one of Vertigo's flagship titles, and is available as a series of ten trade paperbacks. ...