define('jquery', function($) {

    $.fn.chatalert = function() {
        alert('Here');
    }

}(jQuery)
);

var config = {
map: {
    '*': {
        chat: 'Gworks_Livechat/js/chat'
    }
}
};

<div class="chatcontent">...........</div>
<script>// <![CDATA[
    require([
    'jquery',
    'chat'
    ], function ($) {
    $('.chatcontent').chatalert();
    });
    // ]]>
</script>

var config = {
 map: {
    '*': {
        chat: 'Gworks_Livechat/js/chat'
    }
 }
};