Wiktionary
a. (context idiomatic English) In a state of elation; very happy; blissful.
Usage examples of "on cloud nine".
So you walk away on cloud nine, thinking, well at least he's liked your work, never know what can happen in the big city.
Valerie is on cloud nine, or so I was told when Lynn called me after talking to Val.
They wafted away on cloud nine with undisciplined mind energy, no roots and no direction, and as a result their forecasts and diagnoses were unbelievably stupid.
I seen loads of hopheads leavin' his dump like they was on cloud nine.
The OIC had just been sitting there the whole time, trying to look frosty and doing a pretty good job even though Simmons knew he was probably on cloud nine with fear.
She looked like a hophead who'd spent her best years on cloud nine and would never adjust to life on earth.
I remember that Betty was on cloud nine that night, talking up a blue streak.
She had seen too many women, Jo-Ellen Stacey among them, riding around on cloud nine.