The word "How" is used frequently as a greeting in representations of Native American speech. According to the Oxford English Dictionary, the word was originally used by missionary Jean de Brébeuf to indicate an interjection of approval used by the Wyandot (or Huron in French uses); the OED gives the transcription haau.[1] It later became common in popular culture, used (perhaps inaccurately) as a greeting.
It was adopted from the Lakota Sioux word háu which is used by men as a greeting "hello", and is pronounced as the English "how". [2]