[uh-bis-uh l]


of or like an abyss; immeasurable; unfathomable.
of or relating to the biogeographic zone of the ocean bottom between the bathyal and hadal zones: from depths of approximately 13,000 to 21,000 feet (4000 to 6500 meters).

Origin of abyssal

From the Medieval Latin word abyssālis, dating back to 1685–95. See abyss, -al1
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

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Historical Examples of abyssal

British Dictionary definitions for abyssal



of or belonging to the ocean depths, esp below 2000 metres (6500 feet)abyssal zone
geology another word for plutonic
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for abyssal

1690s, used especially of the zone of ocean water below 300 fathoms, from abyss + -al (1). Though the 19th century, abysmal was more common in oceanography.

Online Etymology Dictionary, © 2010 Douglas Harper

Science definitions for abyssal



Relating to the greatest depths of the oceans and to the organisms that live there. The abyssal zone encompasses all depths below 4,000 m (13,120 ft).
Relating to the region of the ocean bottom between the bathyal and hadal zones, from depths of approximately 2,000 to 6,000 m (6,560 to 19,680 ft). The abyssal zone includes nearly two-thirds of the Earth's surface.
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