(fuh see bo) n., (pl. -bos,-boes)
1 an acquaintance established solely through social networking systems that otherwise would have remained some totally unknown person somewhere on the planet
2 one of the millions you have no f***ing clue about past Farmville
3 an innocuous and superficial relationship or connection in lieu of a real one
Instead of going out, they prefer to stay at home and hang with their facebos.