To be in high spirits or to act merry/festive; to get carried away in a cheerful or frivolous mood.
彼女は大学に合格して、しばらく浮かれていた。
She passed the university entrance and was elated for a while.
浮かれすぎて大事な連絡を忘れないように気をつけて。
Be careful not to get so carried away that you forget an important message.
祭りの日は町の人たちがうかれて踊っていた。
On the festival day, townspeople were merrily dancing.