Question

if I have multiple items, set as class="item", is it possible to do something like:

$(".item").mouseover(function(){
        $(!this).hide() // every .item but $(this)
         });

Answer 1

Yes, that’s easily possible:

$('.item').not(this).hide();

You can optimize this a bit by storing the items list:

var items = $('.item');
items.mouseover(function() {
    items.not(this).hide();
});