wtd.el

(defun window-toggle-dedicated (&optional window)
  "Toggle the dedicated flag on a window."
  (interactive)
  (let* ((window (or window (selected-window)))
         (dedicated (not (window-dedicated-p window))))
    (when (called-interactively-p)
      (message (format "%s %sdedicated"
                       (buffer-name (window-buffer window))
                       (if dedicated "" "un"))))
    (set-window-dedicated-p window dedicated)
    dedicated))