Si
来自Big Physics
Safin（讨论 | 贡献）2022年4月27日 (三) 09:14的版本 （建立内容为“Category:etymology == google == [https://www.google.com.hk/search?q=si+etymology&newwindow=1&hl=en ref] early 18th century: from the initial letters of Sanct…”的新页面）
early 18th century: from the initial letters of Sancte Iohannes, the closing words of a Latin hymn (see solmization).
wiktionary
Acronym of Latin Sancte Ioannes, the phrase ending the hymn Ut queant laxis from earlier words of which the other notes of solfège were derived.
etymonline
si
"yes" in Italian and Spanish; from Latin sic "so" (see sic).
