What’s the closest thing to #define in Matlab?

From my question on StackOverflow (CC BY-SA 3.0):

In C, I might do something like this:

#define MAGIC_NUMBER (88)

int foo(int a, int b, int c) {
  return a + b + c + MAGIC_NUMBER;
}

double bar(double x, double n) {
  return x + n + MAGIC_NUMBER;
}

/*
 * ...and so on with many kind-of-long functions using
 * MAGIC_NUMBER instead of writing a literal 88 like so:
 */

double bar(double x, double n) {
  return x + n + 88;
}

What should I do in Matlab? (Needs to work across multiple files.)