In the spirit (heh) of Halloween, the Navajo word ch’į́įdii (English loanword: chindi) means ghost or spirit (malevolent).
It is widely held in Navajo tradition that ch’į́įdii leaves the body after death, taking all that was unbalanced and ‘bad’ from the individual. Navajos that maintain this understanding do not linger around the deceased’s possessions or body – unlike the ch’į́įdii. So much as uttering the name of the deceased can bring the ch’į́įdii looking to infect the living with it’s spirit of unbalance.
In the Christian bible translated to Navajo, ch’į́įdii may refer to demonic spirits. It is understood to also be a form of evil in Navajo churches.
Some Navajo use ch’į́įdii as if to say, “Don’t say that!” in response to anything ranging from the playful to the genuine and serious.