exuberant

The story

1. Latin · derived fromexūberāns
2. Middle French · derived fromexubérant
3. English todayexuberant

From 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.