interj.
Used to express farewell.
n., pl., a·dieus, or a·dieux (ə-dyūz', ə-dūz').
A farewell.
[Middle English, from Old French a dieu, (I commend you) to God : a, to (from Latin ad; see ad-) + Dieu, God (from Latin deus).]
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.