Meiosis is called reduction division because number of chromosomes in daughter cells is reduced to half than that of parent cell.
Explanation;
Meiosis is a type of cell division that takes place in the germ-line cells, it involve division of a parent cell into four daughter cells.
The process of meiosis involves two divisions of the genetic material, namely; meiosis I and meiosis II.
The first division is called the reduction division or meiosis I, this is because it reduces the number of chromosomes from 46 chromosomes or 2n to 23 chromosomes or n.