andyoudaoicibaDictYouDict[and 词源字典]
and: [OE] A word as ancient as the English language itself, which has persisted virtually unchanged since at least 700 AD, and has cognates in other Germanic languages (German und, Dutch en), but no convincing ultimate ancestor for it has been identified
[and etymology, and origin, 英语词源]
and (conj.)youdaoicibaDictYouDict
Old English and, ond, originally meaning "thereupon, next," from Proto-Germanic *unda (cognates: Old Saxon endi, Old Frisian anda, Middle Dutch ende, Old High German enti, German und, Old Norse enn), from PIE *en; cognate with Latin ante, Greek anti (see ante). Phrase and how as an exclamation of emphatic agreement dates from early 1900s.