in reference to a hypothetical cloud of small objects beyond Pluto that become comets, proposed 1949 by Dutch astronomer Jan Hendrick Oort (1900-1992), and named for him by 1968.
updated on August 29, 2019
英语词源词典收录了45867条英语词源词条，基本涵盖了全部常用英语词汇的起源、历史，是研究英语词汇或通过词源学英语的必备工具。