Umu, imu, n. 1. Native earth oven. Ka mata te umu a Kuiwai, wahine a Manaia (T. 83). = hangi. As fire was used in many mystic rites, we find umu in phrases referring to rites in connection with war, pure, makutu, etc., nearly every rite having its distinctive umu. Umu pururangi, some form of tapu, violation of which was supposed to cause destruction of the crops. Umu tupapaku, halo round the moon, which was regarded as a bad omen.
2. Scarf, notch in tree felling. Sometimes called umu whakahinga. = tuamu.
whakaumu, n. 1. Hole dug in the ground to serve as a landmark, or to mark the spot where someone of note has fallen in battle.
2. An incantation to debilitate the enemy.
Williams Dictionary