Frantabulous is a mix of Fabulous and Fantastic. A girl named Fran made the word fantabulous into her own by adding an r. FRANtabulous. People use it to refer to things that are fashionable and cool. Instead of saying fabulous and fantastic, you say Frantabulous.
Sort of like "fabulous" but much more fabulous than the word "fabulous" can convey. Like supercalifragilisticexpialidocius but shorter and easier to spell.
While on a free trip to Italy I won a free titanium frame bicycle and the customs agent let me bring it on the plane for free. What a Fantabulous trip!
12 step recovery jargon referring to someone new who talks about how great life is, now that they're sober. Usually meaning that the person is out of touch with reality.
The new guy seems pretty happy for a dude who has no job, no money and no family. He must be on a pink cloud.