You can attach a custom disabled class to your menu link a
tag that you want to disable and simply remove the default action by using preventDefault and targetting that class, like so:
$(".disabled-link").click(function(event) {
event.preventDefault();
});
Then you can style all events from the .disabled-link
with a grey backdrop or any style you like;
CSS
a.disabled-link,
a.disabled-link:visited ,
a.disabled-link:active,
a.disabled-link:hover {
background-color:#d9d9d9 !important;
color:#aaa !important;
}
Demo