{adj. phr.}, {slang} Too happy to think of anything else; very happy. * /Ada has been on cloud nine since the magazine printed the story she wrote./ * /We were on cloud nine when our team won the state championship./ Compare: ON TOP OF THE WORLD, WALK ON AIR.
ON CLOUD NINE
Meaning of ON CLOUD NINE in English
Slang English vocab. Английский сленговый словарь. 2012