"diving apparatus for reaching great depths," 1947, a name coined by its inventor, Swiss "scientific extremist" Prof. Auguste Piccard, from Greek bathys "deep" (see benthos) + skaphē "light boat, skiff" (see scaphoid).
"life forms of the deep ocean and sea floor," 1891, coined by Haeckel from Greek benthos "depth of the sea," which is related to bathos "depth," bathys "deep, high;" which probably is Indo-European but of unknown origin. Adjective benthal is attested from 1877; benthic is attested from 1902.
"boat-shaped," applied to several parts in anatomy, 1741, from Modern Latin scaphoides "boat-shaped," from Greek skaphoeidēs, with -oeidēs (see -oid) + skaphē "light boat, skiff;" also "basin, trough, a bowl;" literally "thing dug or cut out" (from PIE *skabh-, from root *(s)kep- "to cut;" see scabies). Related: Scaphoidal (1680s).
<a href="https://www.etymonline.com/word/bathyscaphe">Etymology of bathyscaphe by etymonline</a>
Harper, D. (n.d.). Etymology of bathyscaphe. Online Etymology Dictionary. Retrieved $(datetime), from https://www.etymonline.com/word/bathyscaphe