Term for two attacks by one move

If one piece attacks multiple enemy pieces simultaneously, this is called a fork.

All prongs of a fork would be handled by capturing the forking piece.

If one move causes two attacks on the same enemy piece, one a discovered attack and the second an attack by the discovering piece, this is called a double attack, or a double check when the piece under attack is the enemy king.

Both prongs of a double attack would be handled by moving the piece under attack.

What if a move discovers an attack on one enemy piece, and the discovering piece attacks a different enemy piece (or several)?

Such an attack cannot be handled either by capturing attacking piece (because two different pieces are attacking) or moving pieces under attack (because there are several).

Is there any term for such a move?

For the type of move you describe I suggest 'clusterbomb' as many things are attacked and some destruction is inevitable.

For any move which allows a preventable 'clusterbomb' to be played I suggest 'cluster***k'.

It's called a lucky move.