This is just a question about terminology that is used in the beginning of a chapter about phonons.
In a simple cubic crystal, we can consider elastic oscillations in f.i. the  direction. In this direction there is one longitudinal and two transversal oscillation modes. Now my textbook tells that these two transversal oscillation modes can be degenerate. I wonder in which sense the word "degenerate" is used here and I hope that someone can clarify this.