In physics, we say that something is "degenerate" when it exists in more than one "equivalent" versions. What is the proper form of saying that there are n versions of X -- that X is "n-degenerate" or "n degenerate"? I have used the first form in my paper, but the editor changed it to the second. It is possible that they were wrong, hence my question.
N-degenerate is correct here, since the hyphen shows that n modifies degenerate, and not X. So [n-degenerate] X is the meaning, not n [degenerate Xs].
Take American-football player, for another example. Without the hyphen, the player is American, not the football. A general rule of thumb is that when a word modifies an adjective, it is proper to hyphenate.