The word for happiness is, often, the same as the word for luck. Today, I learned something about my own name, which I was always told meant “happiness” in Latin:
In every Indo-European language, the modern words for happiness, as they took shape in the late Middle Ages and early Renaissance, are all cognate with luck. And so we get ‘happiness’ from the early Middle English (and Old Norse) happ — chance, fortune, what happens in the world — and the Mittelhochdeutsch Glück, still the modern German word for happiness and luck. There is the Old French heur (luck: chance), root of bonheur (happiness) and heureux (lucky): and the Portugese felicidade, the Spanish felicidad, and the Italian felicita — all derived ultimately from the Latin felix for luck (sometimes fate).
—From the happiness of virtue to the virtue of happiness: 400 B.C. – A.D. 1780, Darrin M McMahon, Daedalus; Spring 2004
Many thanks to Nassim Nicholas Taleb for sending this to me!