Meaning

adjective joyously unrestrained

adjective unrestrained, especially with regard to feelings

adjective produced or growing in extreme abundance

originFrom Middle French exubérant, from Latin exūberāns, the present active participle of exūberō (“be abundant”). Put together from ex (“out”), and uber (“udder”), and originally would have referred to a cow or she-goat which was making so much milk that it naturally dripped or sprayed from the udder.

Etymology from Wiktionary, CC BY-SA 3.0