from The American Heritage® Dictionary of the English Language, 4th Edition
- adj. Resembling an abyss in depth; unfathomable.
- adj. Very profound; limitless: abysmal misery.
- adj. Very bad: an abysmal performance.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- adj. Bottomless; extremely bad.
from the GNU version of the Collaborative International Dictionary of English
- adj. Pertaining to, or resembling, an abyss; bottomless; unending; profound.
from The Century Dictionary and Cyclopedia
- Pertaining to an abyss; bottomless; profound; fathomless; immeasurable.
- Specifically Pertaining to great depths in the ocean: thus, species of plants found only at great depths are called abysmal species, and also abyssal (which see).
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- adj. resembling an abyss in depth; so deep as to be unmeasurable
- adj. very great; limitless
abysm + -al (Wiktionary)