From wiki:
Chinese
Chi (length) (尺) , a traditional Chinese unit of length ("Chinese foot"), approximately 1/3 of a meter
Chi (mythology) (螭), a dragon in Chinese mythology
Ch'i or qi (氣), "life-force" in Chinese culture
Chi (instrument) (篪), an ancient Chinese transverse flute
Greek
Chi (letter), the Greek letter (uppercase Χ, lowercase χ);
Japanese
Chi (kana), a Japanese kana
地, Japanese character for Earth
other
Chi River, Thailand
Chi, a god in Igbo mythology
in science
A probability distribution in mathematics:
Chi distribution
Chi-square distribution
Chi site, a DNA sequence that serves as a recombination hot spot
Creatinine height ratio
in fiction and popular culture
Chi (magazine), an Italian magazine
Chi (Chobits), a character in Chobits media
Chi, a character in Chi's Sweet Home media
"Chi", a song by Korn from Life Is Peachy