Sagan definition by Webster's New World
Webster's New World College Dictionary Copyright © 2010 by Wiley Publishing, Inc., Cleveland, Ohio. Used by arrangement with John Wiley & Sons, Inc.
Sagan, Carl (Edward) 1934-96; U.S. astronomer & writer
Sagan definition by American Heritage Dictionary
, Carl 1934-1996.
American astronomer noted for research on the possibility of extraterrestrial life and for speculation on the severity of a nuclear winter. His books include Dragons of Eden (1977).