D defs.my
Entry 1 sense Webster, 1913

xi

/zī/ · IPA /zaɪ/
01 adj. The Roman number symbolizing the value eleven. Used after a noun it may symbolize the ordinal number; as, Superbowl XI.
  1. 1.
    The Roman number symbolizing the value eleven. Used after a noun it may symbolize the ordinal number; as, Superbowl XI.
Syn. eleven, 11.