abyssal
/əˈbɪsəl/adjective
1- chiefly technical relating to or denoting the depths or bed of the ocean, especially between about 3,000 and 6,000 metres down〈主技〉深海的; 海底的（尤指离海面3,000至6,000米处）。
1.1
- Geology another term for PLUTONIC (in sense 1).【地质】同PLUTONIC（义项1）。
词源
mid 17th cent.: from late Latin abyssalis 'belonging to an abyss' （see ABYSS）.