How to disable ACE Editor's Find Dialog

It's better to use 'removeCommand' instead of use 'addCommand' with fake handler

editor.commands.removeCommand('find');

Andrei Andrushkevich's answer is now a better and simpler solution.

---

You can redefine the command associated with the shortcut by using editor.commands.addCommand, and then just supply an empty function. This custom definition will take precedence over the built-in one. In this case:

editor.commands.addCommand({
    name: "unfind",
    bindKey: {
        win: "Ctrl-F",
        mac: "Command-F"
    },
    exec: function(editor, line) {
        return false;
    },
    readOnly: true
})

Here's the updated JSFiddle. I didn't find clear documentation, but here's the editor.commands definition and here's where .addCommands() is. (Note: code may have changed since this answer was written.)

Edited as per jcubic's comment