An old Klingon tradition in which the friends of a dead warrior keep watch over the body to drive off predators until the spirit has left for Sto-vo-kor.
Ak'voh is a Klingon custom observed after a warrior dies. His comrades stay with the body and guard it from scavengers, giving the spirit time to depart on its journey to Sto-vo-kor.
It appears at the end of The Ship in 2373. Crewman Enrique Muniz, an engineer close to Miles O'Brien, is wounded when the Jem'Hadar attack an away team salvaging a crashed Dominion warship, and dies slowly during the siege that follows. Worf argues bluntly that Muniz should be told to prepare for death, and he and O'Brien nearly come to blows.
Once the crisis is over, O'Brien sits alone beside Muniz's coffin in the cargo bay. Worf joins him, explains ak'voh, and the two keep the vigil together.