1. 1. An occurrence causing widespread destruction and distress; a catastrophe.
   2. A grave misfortune.
2. Informal. A total failure: The dinner party was a disaster.
3. Obsolete. An evil influence of a star or planet.

[French désastre, from Italian disastro : dis-, pejorative pref. (from Latin dis-; see dis-) + astro, star (from Latin astrum , from Greek astron).]

The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.