How can I remove a non-MAS app from Launchpad without uninstalling? I have a non App Store app installed so the 'X' does not appear when I hold down the icon.

I don't want to uninstall the app, just remove it only from Launchpad.

It's OS X Mavericks
Launchpad Manager will allow you to delete any app from your Launchpad. Just open it, select the app you want to delete and press ⌘⌫.