Is there a term for ‘abandoning your Jewish identity’?
Say you’re born Isaac Cohen, to a good Jewish family.
You change your name to Jim Smith and never practice Judaism.
I’m looking for something stronger than “anglicize” with reference to the name change only. I’m specifically talking historically about emigres in the early 20th c.
Thanks.
Assimilation. Someone undergoing what you described would be called an “assimilated Jew.”
Apostasy. I was under the impression that that term originated WRT abandonment of Catholicism, but I could be wrong about that. In any event, it is now a generic term for the abandonment of any religious faith.
No, apostasy doesn’t really work that way in Judaism. it’s not enough to abandon your religion - you have to actively embrace a different religion. An atheist Jew is still a Jew, just not, in the eyes of the religious, a very good one. The John Smith mentioned in the OP, even if he ate bacon three meals a day and hadn’t been in a synagogue once in his entire life, would still be accepted as a member of an Orthodox *minyan *- if he chose to put himself forward. If he actually converted to Christianity, then all bets are off.
What’s up with this? The Jewish sabbath does not start until tomorrow evening. This question was posted a day and a half early.
Hmm. “Assimilation” sounds so nice.
I was thinking there might be a term that implied betrayal or a bit of self-hatred.
In my Catholic experience, I go with lapsed… but I’ve not actively tried to separate myself from my Catholic roots, I’ve simply stopped attending, and no longer really care about the faith, though I still acknowledge/communicate with God “in my own way.”
I think the Borg would like to meet you.
Reminds me:
Wouldn’t that be “conversion”?
Jewacide?
The Heebie-Jeebies?
You, sir, should be slapped with a wet trout for that. 
Ouch.
That said, I think conversion is definitely the term for someone who embraces a different religion from the one they were part of before.
Conversion is a neutral term - you can convert to and from Judaism. Apostasy is much more negative.
What the OP was asking for, however, was assimilation. It’s the term used to describe Jews who have become culturally indistinguishable from the surrounding gentiles.
I agree with Alessan. “Assimilation” has the added negative connotation of someone who is deliberately and mindfully abandoning Judaism. Someone who is “not-practicing” hasn’t abandoned Judaism, just isn’t observant. Assimilation goes beyond that.
“Do not go gentile in that good night”, perhaps?
Shixa one, half a daven of the other.
My mother would call it, “Breaking your mother’s heart.” But then again she’s Jewish.
Back in the day they used to call it “Hellenization”.
I don’t know if “assimilation” is the right word. It seems to me that “assimilation” can happen somewhat naturally over the course of generations of nobody tries to preserve the cultural heritage.
What the OP describes, however, seems like a more deliberate attempt to obscure a Jewish background.
n.b.: In the earlier part of the 20th century, a name change didn’t mean much. People anglicized their names for some very practical reasons, and some people had their names anglicized for them (Ellis Island, etc.)
There’s a big difference between a mostly-culturally-assimilated nonreligious Jew like me and someone who is actually trying to appear not-Jewish.
If I didn’t want people to know I was Jewish, I could have taken my ex-husband’s anglicized name. I could cut the Yiddish and stereotypically Jewish phrasing out of my speech. Most people don’t think I look Jewish. I could “pass” if I wanted to.
Anyway, I think that’s what the OP is asking about–someone who may not outwardly lie about his Jewish heritage, but for the most part, is “trying to pass” as a gentile.