from The American Heritage® Dictionary of the English Language, 4th Edition
- adj. Of, relating to, or living in the depths of the ocean, especially between about 1,000 and 4,000 meters (3,280 and 13,120 feet).
from Wiktionary, Creative Commons Attribution/Share-Alike License
- adj. Of or pertaining to the parts of the oceans at depths between 1000 and 4000 meters deep.
from The Century Dictionary and Cyclopedia
- Swimming or floating both at the surface of the sea and in its depths; pelagic.
bathy- + pelagic (Wiktionary)