What is eudaimonia? What does the term translate to and what would be an example of it?

Eudaimonia does certainly play an important role in Aristotle's Nicomachean (and Eudemian) Ethics, but he is not the first (nor the last) philosopher to use that term. 
Democritus, the fifth-century natural philosopher, is the first to argue that eudaimonia does not consist of external goods. Plato claims that the person who is just and virtuous will be happy (eudaimon)—this requires both that the parts of the soul be in harmony (Republic) and that the individual approximate the divine harmony of the universe (Timaeus).
For Aristotle, there are two kinds of eudaimonia—the ultimate is the godlike virtue of theoria (contemplation) as laid out in Book X of the Nicomachean Ethics. However, the eudaimonia attainable by humans consists in exercising phronesis (practical wisdom) and living a life that involves not only exercising non-intellectual virtues, but also involves external goods and relationships. 
It is important to note that, even though the term is commonly translated as "happiness," it does not mean pleasure or subjective contentment but is better understood as complete fulfillment. For these reasons, the word is often best translated as "flourishing" or "well-being."

Eudaimonia (Greek: εὐδαιμονία) is a central concept in Aristotle's Nicomachean Ethics, a work that has significantly influenced much philosophical thinking about ethics, morality, and the nature of the good life. 
The Greek term is still widely used by philosophers in modern languages, including English. It means something on the order of "well-being" or "human flourishing." Aristotle himself contrasts it with "hēdonḗ" (Greek:  ἡδονή) or immediate (especially sensual) pleasure. Living the good or eudaimonic life is our ultimate goal, of course; no one would say that they want to live badly or not flourish in some way. The philosophical quandary comes in attempting to define what actually constitutes a good life.
Aristotle himself suggests that it is one of “virtuous activity in accordance with reason.” He sees the ultimate form of eudaimonia as the philosophical life because, as reason is the highest and most distinctively human capability, the best human life is the one most in accord with and most focused on exercising reason. Stoics tended to favor a life undisturbed by the passions (apatheia) in which one attempted to understand and act in harmony with the natural laws of the universe. The Epicureans emphasized a goal of ataraxia (tranquility) and a life somewhat withdrawn from the world, achieving eudaimonia by "cultivating one's garden."
https://plato.stanford.edu/entries/epicurus/