Dual
来自Big Physics
Safin(讨论 | 贡献)2022年4月27日 (三) 11:05的版本 (建立内容为“Category:etymology == google == [https://www.google.com.hk/search?q=dual+etymology&newwindow=1&hl=en ref] late Middle English (as a noun denoting either of t…”的新页面)
late Middle English (as a noun denoting either of the two middle incisor teeth in each jaw): from Latin dualis, from duo ‘two’.
wiktionary
Borrowed from Latin dualis(“two”), from duo(“two”) + adjective suffix -alis
etymonline
dual (adj.)
c. 1600, in grammar, "the form or number relating to two," from Latin dualis "that contains two; the dual number, duality," from duo "two" (from PIE root *dwo- "two"). General sense of "relating to two, expressing two, composed or consisting of two parts" is from 1650s. Related: Dually.