bis-youdaoicibaDictYouDict[bis- 词源字典]
word-forming element meaning "twice," from Latin bis "twice, in two ways, doubly," from Old Latin dvis, cognate with Sanskrit dvih, Avestan bish, Greek dis, Middle High German zwis "twice," from PIE *dwo- "two" (see two). Also the form of bi- used before -s-, -c-, or a vowel.[bis- etymology, bis- origin, 英语词源]