Ajax Cross-Origin Request Blocked: The Same Origin Policy disallows reading the remote resource

JSONP or "JSON with padding" is a communication technique used in JavaScript programs running in web browsers to request data from a server in a different domain, something prohibited by typical web browsers because of the same-origin policy. JSONP takes advantage of the fact that browsers do not enforce the same-origin policy on script tags. Note that for JSONP to work, a server must know how to reply with JSONP-formatted results. JSONP does not work with JSON-formatted results.

http://en.wikipedia.org/wiki/JSONP

Good answer on stackoverflow: jQuery AJAX cross domain

   $.ajax({
        type: "GET",
        url: 'http://www.oxfordlearnersdictionaries.com/search/english/direct/',
        data:{q:idiom},
        async:true,
        dataType : 'jsonp',   //you may use jsonp for cross origin request
        crossDomain:true,
        success: function(data, status, xhr) {
            alert(xhr.getResponseHeader('Location'));
        }
    });

We can not get the data from third party website without jsonp.

You can use the php function for fetch data like file_get_contents() or CURL etc.

Then you can use the PHP url with your ajax code.

<input id="idiom" type="text" name="" value="" placeholder="Enter your idiom here">
<br>
<button id="submit" type="">Submit</button>
<script type="text/javascript">
$(document).ready(function(){
    $("#submit").bind('click',function(){
        var idiom=$("#idiom").val();
        $.ajax({
            type: "GET",
            url: 'get_data.php',
            data:{q:idiom},
            async:true,
            crossDomain:true,
            success: function(data, status, xhr) {
                alert(xhr.getResponseHeader('Location'));
            }
        });

    });
});
</script>

Create a PHP file = get_data.php

<?php
  echo file_get_contents("http://www.oxfordlearnersdictionaries.com/search/english/direct/");
?>

Place below line at the top of the file which you are calling through AJAX.

header("Access-Control-Allow-Origin: *");