Jew: Ethnicity, Religion, Nation, Self-Defined, or None of the Above?

As an activist and an anarchist, I run into the thorny problem of the word “Jew” fairly frequently. Just recently, for example, a comrade of mine – a tenured university professor – was quoted in a newspaper complaining about the “Jewish lobby.” His political enemies on Wikipedia used this as an excuse to smear him as an anti-semite, and I was threatened with banning for attempting to stop them, since they had a “citation” for it. Two weeks later the newspaper ran a full retraction and apology, because he hadn’t used the word “Jew” at all, he had referred in fact to the “Israeli lobby.”

I, myself, here on Fluther, have found myself the target of accusations of anti-semitism because of my belief that no nation is legitimate, whether it’s Kanada, Amerika, Mexiko, Kuba, Palestine, or Israel. Ironically, my own comrades have sometimes accused me of being a racist and imperialist because I won’t give typically leftist, unconditional support for Palestinian nationalism.

So what does the word “Jew” mean to you? Is it a cultural heritage of fashion, cuisine, and tradition? An ethnic, genetically-derived phenotype? A legally-defined identity based on nationality? A religion that anyone can join? A religion that only a rigidly-defined group can join? Is it enough to simply call oneself a Jew to be a Jew, or do other conditions apply?

More importantly, do you believe that there is an objective definition at all, or that it’s possible to have one?