adjective very good. A blend of 'fantastic' and 'fabulous'. Contemporary UK gay usage US, 1958
fantabulous
slang Excellent or outstanding. A portmanteau of "fantastic" and "fabulous." Fantabulous! I'll meet you at 8:00 then.A: "OK, I'll give you guys a chance." B: "Fantabulous—you won't regret it!"
Fantabulous!
exclam. Great! (A blend of fantastic and fabulous.) You’re here at last. Fantabulous! Where did you get that fantabulous haircut. There’s no two hairs that are going in the same direction! Fab! Fab! Fab!