In
quantum mechanics, two
states are said to be degenerate if they possess the same
energy level.
For example, in the particle in a box problem, assuming a three-dimensional potential well with equal lengths in all dimensions, the following states are degenerate:
(4,3,1)
(4,1,3)
(3,4,1)
(3,1,4)
(1,4,3)
(1,3,4)