To Be Happy
To Be In High Spirits, To Be Elated
intransitive verb, ichidan verb
浮く means "to float," and 浮かれる draws on that metaphor of "floating" to mean to be happy, to be in high spirits, or to be elated. We have the same metaphor in English — think of being "on cloud nine."
The reading comes from 浮く, so if you know that you' are going to be happy and you won't have a care (かれる) in the world!
たくさんの人がオリンピックに浮かれすぎている。
Many people get too carried away by the olympics.