Apple - Can I disable Dashboard in Mountain Lion?

With macOS 10.10 Yosemite or later, you can go to
System PreferencesMission Control and switch Dashboard to Off.

                                                      

On any OS with Dashboard, you can disable it through Terminal with the following command:

defaults write com.apple.dashboard mcx-disabled -boolean YES && killall Dock

It can be re-enabled with:

defaults delete com.apple.dashboard mcx-disabled && killall Dock

If you don't want to use Dashboard at all, free Apps are available to disable & enable (if you wish to revert) it including:

  • Bye Bye Dashboard
  • ‘Disable & Enable Dashboard’ Utility

EDIT

Alternatively see also this Youtube tutorial published on August 9th 2013 entitled "Removing the Dashboard (MacMost Now 902)"