Jewish naming traditions vary widely, especially between the Ashkenazic and Sephardic communities.
According to Sephardic tradition, babies are generally named after living relatives, based on a source from the Babylonian Talmud (Shabbat 134a), in which a child was named after Rabbi Natan while he was still alive. In many Sephardic families, it is customary for the father to name the first child, using a name of a living relative from the father's side of the family. Rav Ovadiah Yosef says that the source of this custom is Genesis 38: 3-5 (Parashat VaYeshev), where the Torah teaches that Judah named his first son, Er, and his wife named his second son, Onan.
According to Ashkenazic tradition, on the other hand, babies are generally named after deceased relatives, as a means of perpetuating the memory of the deceased relative and as a means of forming a bond between the soul ("neshamah") of the baby and the soul of that deceased relative. Many Ashkenazic halachic authorities say that it is impermissible to name babies after living relatives. One reason for this custom is that naming after a living person might give the appearance of one's waiting for that person to die. Another reason for this custom is that it is considered disrespectful to living relatives to refer to them by their first names or to use their first names in their presence (when calling the grandchildren) while they are still alive (Shulchan Aruch, Yoreh Deah (YD) 240:2).
Some Ashkenazic Jews follow the custom of giving the mother the right to name the first child, using a name of a deceased relative from the mother's side of the family.
When naming a baby 'after' a relative (a living relative, in the case of Sephardic Jews, or a deceased relative, in the case of Ashkenazic Jews), the most prevalent tradition is to give the child the exact Hebrew or Yiddish name of the relative. However, some Ashkenazic authorities say that it is impermissible to use the exact Hebrew or Yiddish name of a deceased relative if one of the child's parents has the same Hebrew or Yiddish name as that deceased relative.
If there is a separate 'English' name (as opposed to calling the child the same name in Hebrew/Yiddish and in English/vernacular), some families follow the custom of picking an English name whose first letter has the same sound as the first Hebrew letter of the Hebrew name. For example, a child who is named after a grandmother whose Yiddish name was "Bayla" might be given an English name that begins with a "B," such as "Betty," "Billie," or "Brittany." Alternatively, some families select an English name that has a similar meaning to the relative's Hebrew/Yiddish name. For example, a child who is named after a grandmother whose Yiddish name was "Bayla" or whose Hebrew name was "Yaffa" might be given an English name that also means "beautiful," such as "Belle." For Hebrew or Yiddish names that have a common English equivalent, it is most traditional to bestow that English name upon the baby if the parents aren't comfortable with giving their child a Hebrew or Yiddish name. For example, the common English equivalent for the Hebrew name, "Yosef," is "Joseph." It certainly doesn't make sense to give a child who has the Hebrew name, "Yosef," the English name, "Jacob," because "Jacob" has a clear Hebrew equivalent, which is "Yaakov."
Of course, if all of a couple's closest relatives have already been honored by having a child named after them, there are other Jewish baby naming traditions among both Ashkenazic and Sephardic Jews, including the following:
1) giving a baby a name that has some connection to the Jewish holiday that is in closest proximity to the child's birth. For example: A child born on or near Purim might be given the Hebrew name, "Mordechai" or "Esther." A child born on or near Sukkot might be given the Hebrew name, "Hadas" (myrtle tree). A child born on or near Chanukah might be given the Hebrew name "Yehudah" (in honor of Judah/Yehudah Maccabbee) or "Nes-yah" ("miracle of God," in honor of the miracle of the oil) or "Orli" ("my light," in honor of the Chanukah menorah lights.)
2) giving a baby a name from the Torah or Haftarah portion corresponding to the week of birth. For example: A child born last week, might have been given the Hebrew names, "Moshe" or "Miriam," since these biblical heroes featured prominently in Parashat B'Shalach, or the Hebrew names, "Devorah," or "Barak" or "Yael", since these biblical heroes featured prominently in last week’s Haftarah from the Book of Judges/ Shoftim. Or, a child could have been given the Hebrew name "Shir" or "Shirah," in honor of the Song of the Sea (Shirat HaYam) in the Torah portion or the Song of Deborah (Shirat Devorah) in the Haftarah that is read on Shabbat Shirah (The Sabbath of Song).
Perhaps it would be helpful to some people to describe how my husband and I named our three children, following the Ashkenazic tradition of naming after deceased relatives:
1) My daughter, Rivkah, is named after my grandmother, Regina Post z"l, whose Hebrew name was "Rivkah." My daughter has the same name, "Rivkah," in both Hebrew and English. (Incidentally, there are two other relatives in our family who are named after my Babi Gina and both are named "Rivkah" in Hebrew, but not in English; one is named "Rebecca" and the other is named "Rikki.")
2) My daughter, Eva, is named after my great-grandmother, Eva Bodenstein Grundleger z"l, whose Hebrew name was "Chavah." My daughter has the same English name, as well as the same Hebrew name, "Chavah," as my Babciu Eva.
3) My son, Ariel, is named after my husband's great-grandfather, Alvin Wyner z"l, whose Hebrew name was "Avraham." My son's name, which means, "lion of God," is the same in Hebrew and in English. We didn't give him the Hebrew name, "Avraham," because my husband's Hebrew name is "Avraham" & we followed the Ashkenazic custom of NOT bestowing the name of living relative on a child. So, we chose a different name that began with the Hebrew letter, "Aleph,” and the English letter, "A."
Answered by: Rabbi Lisa Malik