abyssal

The story

1. Latin · derived fromabyssus“abyss”
2. Medieval Latin · derived fromabyssalis
3. English todayabyssal

First attested in the 1690s. From Medieval Latin abyssalis, from Latin abyssus (“abyss”) + -alis (“-al”). Equivalent to abyss + -al.

First known use, by meaning

• First attested in the mid 17ᵗʰ century. Belonging to, or resembling, an abyss; unfathomable.
• First attested in the mid 19ᵗʰ century. Of or belonging to the ocean depths, especially below 2000 metres (6500 ft): abyssal zone.
• First attested in the late 19ᵗʰ century. Pertaining to or occurring at excessive depths in the earth's crust; plutonic.