Degenerate square matrix refers to a matrix whose elements are all zero except 1 on the main diagonal. Degenerate square matrix is a special kind of square matrix, its order (number of rows or columns) is greater than 1, but its determinant is equal to zero.

The inverse matrix and determinant of degenerate square matrix have special properties in mathematics. The inverse matrix of a degenerate square matrix is similar to the original matrix, and its elements are all zero, only the elements on the main diagonal are 1. The determinant value of degenerate square matrix is 0.