Noun: A short pointless web page attached to a web domain name. The page is used to give the domain name web presence, thus allowing it appear in a search engine such as google. The page will usually contain a few key words, or a logo of some sort.
if you were trying to sell a domain name, you might attach a blirg to it. the purpose: when a potential buyer dose a google search of the word, it would show up in the list.