vertex (n.)youdaoicibaDictYouDict[vertex 词源字典]
1560s, "the point opposite the base in geometry," from Latin vertex "highest point," literally "the turning point," originally "whirling column, whirlpool," from vertere "to turn" (see versus). Meaning "highest point of anything" is first attested 1640s.[vertex etymology, vertex origin, 英语词源]