adj.
- Resembling an abyss in depth; unfathomable.
- Very profound; limitless: abysmal misery.
- Very bad: an abysmal performance.
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.