"pherese" > "phrase" "cloud nine" - I'm on cloud nine right now! = I'm really happy right now! After I won the race, I was on cloud nine. = After I won the race, I was really happy. Basically, it's just an expression to show happiness, excitement, or joy. Let me know if that makes sense.^^

It means "bliss", "beatitude", "felicity". Synonym: the seventh heaven

"cloud nine"= extremely happy

n. Informal A state of elation or great happiness: was on cloud nine after winning the marathon.