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[uh-bis-uh l] /əˈbɪs əl/
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
1685-95; < Medieval Latin abyssālis. See abyss, -al1 Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2015.
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Examples from the web for abyssal
  • From the abyssal depths to the tropical shallows, the ocean teems with myriad creatures.
  • The abyssal plains of the world ocean floors are not nearly as deep as that.
  • For instance, abyssal grenadier fish were confined to valleys on either side of the ridge.
  • There is a census of coastal waters and a census of the abyssal plains, a census of coral reefs and a census of seamounts.
  • In the abyssal plains, moreover, the map reveals its second weakness: there it tends to show too much topography.
  • Submersibles alone enable us to explore the abyssal depths.
  • The abyssal depths had always been regarded as a desert, incapable of supporting life.
  • Some mineral resources, such as manganese nodules, occur primarily on the deep ocean areas known as abyssal plains.
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
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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
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abyssal in Science
  1. 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).

  2. 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.

The American Heritage® Science Dictionary
Copyright © 2002. Published by Houghton Mifflin. All rights reserved.
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