My brother raised an issue a few years back, after the terrible murders in the chabad house in mumbai, India. Jews began talking about the city, and he was concerned that this was a violation of ושם אלהים אחרים לא תזכירו based on our gemara that even to refer to the city kalnavo was a problem, if not for the fact that it is an avoda zara mentioned in the Torah and therefore permitted to say. The question was presented to Rav Shternbach, and I had some thoughts of my own. I am posting both emails below.
Rav Shternbach read through the e-mail. He holds it isn't a problem for us to say because the Gemara is only referring to a case where it is commonly known that the name is for an avodah zara. However, in a case where the common person has no idea what the name is and it is just used to describe a day, month, or place. There in no problem. I told him that I thought you anticipated such a heter and that is why you reiterate more than once that you think it is common knowledge. 1- The information is readily available to anyone that looks into it. 2- The name was changed so recently that people know why it was changed. However, Rav Shterbach feels that only people that look into it will know this. the common person living outside India has no idea what the name is for - as Rav Moshe said "I had no idea until I read the e-mail - Did you? Ask anyone you know and see what they say." He thinks this is the real heter for the months and days of the week.
I asked him what about a person who goes to India and there everyone knows why it was named Mumbai. Is it considered common knowledge there? I didn't get a straight answer and he had to run so I will try to push him on that.
In short - he disagrees with the premise that it is well known. We don't Judge by the actual place but the general common knowledge in the world even if it is information that is easily attainable. I assume this response/svara won't excite you that much and I haven't time to re-read the e-mail to see if there are any proofs against this Sevara. I Will also Bli neder ask him if there is a Proof for this definition of the Halacha.
Let me know if you have any other follow up questions.
Rabbi N. Lauer
regarding the sevara of r' shternbach - i think it is definitely plausible and would like to build on it. Rather than distinguishing between how many people know it is avoda zara, i think there is an additional distinction. Rashi explains in sanhedrin 63b that the city "kalnabo" was assur to say (if not for the fact that it is mentioned in the torah) because "the city is called after the avoda zara inside of it". Meaning, that it is not speaking of a case where a city is named after an avoda zara, rather it is speaking where the city is ta'fel to the avoda zara. It would be similar to the way we refer to yeshivos - like "lakewood" or "baltimore" [or washington heights :)], just the reverse. the city isn't named after the yeshiva, but in the reference you make the city is ta'fel to the yeshiva. Here too, rashi says that when you refer to the city you are in actuality referring to the avoda zara since the entire city is tafel to the avoda zara. But, in mumbai the city is not tafel to the avoda zara, it was just named after an avoda zara. For example, if they renamed New York and started calling it Jesus, it would still be permitted to refer to the city by its new name.
R' Avi Lebowitz
Jewish Study Network
When I presented this to Rav Nota Greeblatt he pointed out that rashi is difficult. How did rashi know that kalnavo was called that because of the avoda zara that was inside of it? Rashi most likely didn't know the metzi'us, rather he knew the halacha that it is only assur when the reference is to the avoda zara that is IN the city, so that the entire city becomes subordinate to that avoda zara. Rashi holds that if a city was simply named the name of an avoda zara to show kavod to an avoda zara that exists somewhere else, it would not be assur to refer to the city by that name. That is how rashi knows that kalnavo must have contained an actual idol inside it, to which the entire city was referred to.