$(document).ready(function(){
  //lowercase, kill 'http://', kill stuff after first '/', kill 'www.' if there
  var ref = document.referrer.toLowerCase().split('http://').pop().split('/').shift().split('www.').pop();
  var base = location.href.toLowerCase().split('http://').pop().split('/').shift().split('www.').pop();
  //no referrer was passed OR referrer is from this website
  if (!document.referrer || ref==base) {$('div.block-similarterms').hide();}
  //unhide similar by terms div
  else {$('div.block-similarterms').show();}
})