Adai (also Adaizan, Adaizi, Adaise, Adahi, Adaes, Adees, Atayos) is an extinct Native American language that was spoken in northwestern Louisiana.

It was once proposed that there may be a connection between Adai and the nearby Caddoan languages, but this now seems unlikely.

[2] Adai is known only from a list of 275 words from 1804 by John Sibley.

[3] The manuscript word list below has been reproduced from Grant's (1995) transcriptions.

[2] (Note: Due to the poor printing in Grant (1995), the text below may not be entirely accurate and will need to be re-checked.)