Pronunciation: (dim'out"), [key]
1. a reduction or concealment of night lighting in wartime to make the source less visible to an enemy from the air or sea.
2. a reduction of night lighting caused by a failure in an electric generating system or a reduction in its output. Also,dim'out".Cf. blackout (def. 2), brownout.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.