abbreviation of ultraviolet, by 1928.
"beyond the violet end of the visible spectrum," 1840, from ultra- "beyond" + violet. Ultra-red (1870) was a former name for what now is called infra-red.
updated on October 27, 2010
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。