abyssal plainyoudaoicibaDictYouDict[abyssal plain 词源字典]
"An extensive level area of the deep ocean floor, typically situated between the foot of the continental rise and an oceanic trench and covered with a smooth layer of sediment", Late 19th cent.; earliest use found in Thomas Huxley (1825–1895), biologist and science educationist.[abyssal plain etymology, abyssal plain origin, 英语词源]