Declaring a simple constant is easy too. Let's say we want to make a constant called 'FIVE':

     5 constant five

Now you can use 'FIVE' like you would '5'. E.g. this will print five spaces:

     five spaces

The same rules for declaring words apply for constants. You can't use a name that already has been taken. A constant is a word too! And whitespace characters are not allowed. Note that 4tH is not case- sensitive. By the way, '5' is a literal expression. You can't take it from the stack or calculate it.