How do you disable an application specific hotkey, for example, "Command-P"? In many applications, Command-P is used to print. 
My fingers are accustomed to emacs settings and reflexively press Command-P not for printing but for browsing history. It's annoying to see the print pop-up window every time when I press Command-P. I don't need a shortcut to print.
How do you block a shortcut globally?
This can be achieved by remapping the Print shortcut to a different shortcut that is out of the way, unused and unlikely to be pressed.


Open System Preferences → Keyboard → Shortcuts → App Shortcuts.
Click + to add a new shortcut.
Application: All Applications

Menu Title: Print… (that's a 'proper' ellipses by the way, use copy-paste if necessary)

Keyboard Shortcut: Set it to something out of the way.


Click Add.


Now, the Print command is set to a random keyboard shortcut, freeing up ⌘P.