abyssal

adjective abys·sal \ ə-ˈbi-səl \

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Definition of abyssal

1 : unfathomable b

2 : of or relating to the bottom waters of the ocean depths

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Recent Examples of abyssal from the Web

Even here, though, abyssal tuba notes exposed a sonic substratum.

— alex ross, The New Yorker, "The L.A. Philharmonic Celebrates Iceland," 21 Apr. 2017
Before New Horizons flew by, scientists thought there wouldn’t be much in the way of geological activity happening out there on the fringe, where temperatures are decidedly abyssal and materials tend to freeze in place.

— National Geographic, "5 Amazing Things We’ve Learned a Year After Visiting Pluto," 14 July 2016

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'abyssal.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

Did You Know?

Abyssal is a relatively infrequently used word, though it's derived from the more prevalent noun, "abyss." In contrast, the adjective "abysmal" is more common than its corresponding noun "abysm." All four terms descend from the Late Latin word abyssus, which is in turn derived from the Greek abyssos ("bottomless"). "Abyss" and "abysm" are synonymous (both can refer to the mythical bottomless pit in old accounts of the universe or can be used more broadly in reference to any immeasurably deep gulf), but the adjectives "abyssal" and "abysmal" are not used identically. "Abyssal" can mean "incomprehensible," but it's most often found in contexts referring to the bottom of the sea. "Abysmal" shares the oceanographic sense with "abyssal," but it more frequently means "immeasurably deep" or "absolutely wretched."