Most of the time people ask how to add new keybindings to Emacs and that makes perfect sense. Occasionally, however, the topic of removing keybindings also emerges - e.g. recently Paredit added a keybinding that messed up some REPL mode that were enabling it. The solution was to remove the problematic keybinding:

(define-key paredit-mode-map (kbd "RET") nil)

Basically to remove a keybinding you just have to set it to nil. This works both for mode-specific keybindings (as demonstrated above) and for global/local keybindings:

(global-set-key (kbd "C-e") nil)

;; local keybindings are specific only to the current buffer
(local-set-key (kbd "C-e") nil)

You can also use commands like global-unset-key and local-unset-key, e.g. like this:

(global-unset-key (kbd "C-e"))

;; local keybindings are specific only to the current buffer
(local-unset-key (kbd "C-e"))

As a bonus, global-unset-key and local-unset-key can also be used interactively (with M-x).

But wait, there’s more! The bind-key package, that’s used internally by use-package and is available on GNU ELPA, can also come in handy for removing keybindings. It features the macro unbind-key that does exactly what we need. Here’s one example usage:

;; To unbind a key within a keymap (for example, to stop your favorite major
;; mode from changing a binding that you don't want to override everywhere),
;; use `unbind-key':
(unbind-key "C-c x" some-other-mode-map)

Note that the terminology when it comes to removing keybinding is pretty messy as often people use “remove”, “unset” or “unbind” interchangeably. That’s usually fine, but there’s a subtle difference when there’s a parent keymap involved. When unsetting a key in a child map (e.g. with define-key), it will still shadow the same key in the parent keymap. Removing the binding will allow the key in the parent keymap to be used. Everything mentioned in this article so far, except unbind-key, unsets a keybinding.

One more thing… To overwhelm you even further Emacs 29 introduces keymap-unset that can both unset or unbind a keybinding depending on how it’s used:

;; unset a binding
(keymap-unset clojure-mode-map (kbd "C-c C-z"))

;; remove a binding
(keymap-unset clojure-mode-map (kbd "C-c C-z") 'remove)

Probably that function will become the golden standard going forward.

That’s all I have for you today. Short, sweet and maybe even a bit useful.

P.S. Also check out this follow-up article that discusses in more detail the topic of “unsetting vs unbinding”.