/*redirects if contains specific word */
function redrect_if_URL_contains(){
?>
 <script>
	 if (window.location.href.indexOf("custom_word") > -1) {
   window.location.href = 'https://yoursite-newURL.com/'; 
};
 </script>
<?php
}
add_action('wp_footer', 'redrect_if_URL_contains');


--------------------------------------------------------------------


/*redirects if contains specific word after few seconds */
function redrect_if_URL_contains(){
?>
 <script>
	 setTimeout(function () {
if (window.location.href.indexOf("custom_word") > -1) {
   window.location.href = 'https://yoursite-newURL.com/'; 
}}, 5000);
 </script>
<?php
}
add_action('wp_footer', 'redrect_if_URL_contains');