Wordnet 3.0
NOUN (2)
1. the cardinal number that is the sum of ten and one;
[syn: eleven, 11, XI]
2. the 14th letter of the Greek alphabet;
ADJECTIVE (1)
1. being one more than ten;
[syn: eleven, 11, xi]
The Collaborative International Dictionary of English v.0.48:
xi \xi\, adj. The Roman number symbolizing the value eleven. Used after a noun it may symbolize the ordinal number; as, Superbowl XI. Syn: eleven, 11. [WordNet 1.5]

