n. The state of being concomitant; a being together or in connection with another.n. In Roman Catholic theology, the coexistence of the body and blood of Christ in the single eucharistic element of bread, so that those who partake of the consecrated host receive him in full. Also concomitation.n. In mathematics, a relation between two sets of variables such that, when those of one set are replaced by certain functions of themselves, those of the other set are also replaced by certain determinate functions of themselves.