1.an extremly massive and huge person; one who is the size of 40 people; a fat ass
2. One who eats 24/7 while simultaneously being an annoying prick (I.E stealing, saying offhand remarks and telling lies about girls his ugly ass has supposedly slept with)
Holy shit! That Roo is fat as hell! There is a Roo eating all my food!
An absolutely legend who loves peen, has a peen, and appreciates the awesomeness of peen. A Roo is made of awesome and brings fun to MSN orgies in epic proportions.
...the definition speaks for itself really. If you don't have a Roo, then I'm guttedfor you.