It means all sorts of lovely things: bubbling, effervescent (which is next week's word - also mine, also went on that adolescent list. detect a pattern here?), boiling over, overflowing with enthusiasm, high spirits, showing much exuberance or exhilaration.
I don't think I need to explain why I like it.
It's also apropos of this mid-April Sunday morning here in Santa Fe. The weather is warming and the desert is springing into green life. A wren has a nest outside my office window and she sings the loveliest trilling song. Yesterday I bought hanging baskets of flowers and their bright colors bring out the blue in the sky.
I associate "ebullient" with that adolescent time of life, too, when I felt full of high spirits and the world held infinite possibilities. On my best days, I reconnect with that, with that sensation of burgeoning sexuality and creativity. Like the flowers, I blossom in the sunshine, showing off my best and brightest colors.
Happy Spring!
