An ebullient person is someone who is bubbling with excitement. This adjective originates from the Latin bullire, which means to bubble out. Ebullient also has an archaic meaning which refers to the roiling of a boiling liquid.
Here are some examples of the word found in literature:
“To the Kathakali Man these stories are his children and his childhood. He has grown up within them. They are the house he was raised in, the meadows he played in. They are his windows and his way of seeing. So when he tells a story, he handles it as he would a child of his own. He teases it. He punishes it. He sends it up like a bubble. He wrestles it to the ground and lets it go again. He laughs at it because he loves it. He can fly you across whole worlds in minutes, he can stop for hours to examine a wilting leaf. Or play with a sleeping monkey’s tail. He can turn effortlessly from the carnage of war into the felicity of a woman washing her hair in a mountain stream. From the crafty ebullience of a rakshasa with a new idea into a gossipy Malayali with a scandal to spread. From the sensuousness of a woman with a baby at her breast into the seductive mischief of Krishna’s smile. He can reveal the nugget of sorrow that happiness contains. The hidden fish of shame in a sea of glory.”
― Arundhati Roy, The God of Small Things
“Time and again I, too, have felt so full of luminous torrents that I could burst – burst with forms much more beautiful than those which are put up in frames and sold for a stinking fortune. And I, too, said nothing, showed nothing; I didn’t open my mouth, I didn’t repaint my half of the world. I was ashamed. I was afraid, and I swallowed my shame and my fear. I said to myself: You are mad! What’s the meaning of these waves, these floods, these outbursts? Where is the ebullient, infinite woman who, immersed as she was in her naiveté, kept in the dark about herself, led into self-disdain by the great arm of parental-conjugal phallocentrism, hasn’t been ashamed of her strength?”
— Hélène Cixous, The Laugh of the Medusa