We get the "Ethics" part—these lectures are all about being good, happy, and generally pleasant to be around. Easy-peasy.
But what in the name of all that is ethical does "Nicomachean" mean?
Trick question: it's a name, not a word.
There's speculation over whether The Nicomachean Ethics was named in remembrance of Aristotle's father—named Nicomachus—or to honor his own son—also named Nicomachus.
Aristotle's son (talk about living up to a family legacy) edited Aristotle's written works. The Nicomachean Ethics—along with an earlier inquiry called the Eudemian Ethics—are part of a larger conversation about community that culminates in his work Politics.
Taken together, these works emphasize Aristotle's conviction that the political art is the highest good—since it encompasses the good ends desired by every part of the human community. Of course, since we've read The Nicomachean Ethics, we also know that Aristotle pushes the career path of "philosopher" pretty hard, too.