"File scope" is also potentially incorrect - if the code has several nested blocks in the file, only those declared in the outer-most block could be considered to be "File scope".

The correct terminology is "lexical scope".

From "perldoc -f my" :
.... local (lexically) to the enclosing block, file, or "eval".

In this case, the subroutine is accessing a variable declared in an enclosing block.
I suppose this could be considered "global to the subroutine".