xi
/saɪ/noun
1- the fourteenth letter of the Greek alphabet (Ξ, ξ), transliterated as 'x'希腊字母表中第十四个字母（译写为x）。
1.1
Xi
followed by Latin genitive Astronomy the fourteenth star in a specified constellation【天文】ξ星（星座中第十四颗星）：Xi Cygni.
天鹅座ξ星。
词源
Greek.