title: Name of the Gtk+ widget used in the gnome tweak tool as side menu
body: <p><a href="https://i.stack.imgur.com/CJbYq.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/CJbYq.jpg" alt="Gnome Tweak Tool"></a></p>
  
  <p>Name of that Gtk widget on the side which has options: "Apperance", "Desktop" etc.</p>