One part of a pair that is so close that it seems as though sometimes they are attached by an umbilical cord
Umbies - the pair of people who are practically biologically attached
"God Margaret and Max are always together, they need to cut the fucking umbilical cord"
"No its ok, they're totes umbies and we've all learned to accept it."
"Wow, I'm surprised to see you without your umbie"
me. the one and only known umbin in the world. Serious its my real name. if u want to know what it really means you must go to www.umbin.com
hi my name is umbin, but you can call me umbie