A portmanteau so appropriately coined when the picture of a young woman named Abby was subjected to the manipulation of the iPhone application 'Fat booth' which subsequently produced a fattened version of the aforementioned image.
It is a blend of the words 'Fat' and 'Abby'
Guy: Hey Fabby!!!
Abby: The name's Abby
Guy: Its Fabby now
Fabby: What the..