I don't know what else you're loading in your project, but this usually happens with people working with popular CMS frameworks, that uses different plugins, etc creating a javascript conflict.
Have a read here http://api.jquery.com/jquery.noconflict/ about how to avoid this.
Your solution should be something like this:
jQuery.noConflict();
(function( $ ) {
$(function() {
$(document).ready(function() {
// validate signup form on keyup and submit
$("#feedback").validate({
errorClass:"errors",
rules: {
nameid: {
required: true
}
},
messages: {
nameid: {
required: "Please enter a name"
}
}
});
});
});
})(jQuery);
Hope this helps!