wp_unregister_sidebar_widget( int|string $id )

function wp_unregister_sidebar_widget($id) {

	/**
	 * Fires just before a widget is removed from a sidebar.
	 *
	 * @since WP-3.0.0
	 *
	 * @param int $id The widget ID.
	 */
	do_action( 'wp_unregister_sidebar_widget', $id );

	wp_register_sidebar_widget($id, '', '');
	wp_unregister_widget_control($id);
}