Cassini division: Meaning and Definition of

Cassi'ni divi"sion

Pronunciation: [key]
— Astron. Astron.
  1. a 3000-mi. (4800-km) wide dark region that separates the middle and outermost rings of the planet Saturn.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.