1. 
   Pop-under
   Automatically launched internet advertisement that appears in a small window behind another webpage. See ‘Pop-up'.
   Found op http://www.cim.co.uk/resources/glossary/home.xhtml?letter=m
   
   
2. 
   Pop-under
   Automatically launched internet advertisement appearing behind another webpage.
   Found op http://www.chriswallcreative.co.uk/glossary.htm
   
   

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