a·bys·sal 
(ə-bĭsəl)
(ə-bĭsəl)adj.
1. Abysmal; unfathomable.
2. Of or relating to the great depths of the oceans.
3. Of or relating to the region of the ocean bottom between the bathyal and hadal zones, from depths of approximately 2,000 to 6,000 meters (6,500 to 20,000 feet).
- diabetic
- diabetic ketoacidosis
- diabetic neuropathy
- diabetic retinopathy
- diable
- diablerie
- diablo
- diabolic
- diabolical
- diabolically
- diabolicalness
- diabolism
- diabolist
- diabolize
- diacetylmorphine
- diachronic
- diachronically
- diachrony
- diaconal
- diaconate
- diacritic
- diacritical
- diacritically
- diadelphous
- diadem