The complement or reciprocal of an act or thing.
Certain activities and things culturally require complements: The killing of a person in warfare traditionally required killing another; sacrificing a bless-offering, duyduyah, for a married couple requires a second in a year or two; the killing of a wild pig requires that another be killed; when those who have enacted a headhunting ritual, bahbah, dance, they must repeat it to make it complete; one who is chosen to lead in the construction of a new upland field, pang'u 2, is chosen again two or three years later.