### Definitions Found:

# (of a square matrix) Having a zero determinant

- singular(of a square matrix) Having a zero determinant
- adjointsquare matrix obtained from a given square matrix and having the property that its product with the given matrix is equal to the determinant of the given matrix times the identity matrix
- adjointssquare matrix obtained from a given square matrix and having the property that its product with the given matrix is equal to the determinant of the given matrix times the identity matrix
- cofactorsThe quantity obtained from a determinant or a square matrix by removal of the row and column containing a specified element
- eigenvaluesAny number such that a given matrix minus that number times the identity matrix has a zero determinant
- eigenvalueAny number such that a given matrix minus that number times the identity matrix has a zero determinant