If an adult undergoing Brit Milah never received a Hebrew name, then he chooses a name for himself at the time of his Brit. Many people decide to name themselves after deceased relatives or famous Biblical figures, but the decision is a personal one, and each individual must choose the name he feels most comfortable with.

The Names Guide
A:
Abba, Abir, Abiri, Achi, Achiezer, Achimelech, Achinoam, Achishia, Achitzedek, Adam, Adar, Addar, Adir, Adon, Aharon, Akavya, Akiva, Alexander, Alon, Alter, Aluf, Aluph, Ami,Amiel, Amir, Amnon, Amos, Amram, Anshil, Arel, Ariel, Arik, Arye, Aryeh, Asa, Asher, Atid, Av, Avi, Avichayil, Aviezer, Aviezri, Avigal, Avimelech, Avinadov, Avinatan, Aviner, Avinoam, Aviram, Avishai, Avishalom, Aviv, Avner, Avraham, Azriel

B:
Baal, Bani, Bar, Baruch, Bar Yochai, Ben, Ben Ami, Ben Baruch, Bunim, Ben Ezra, Ben Tov, Ben-Tziyon, Ben-Yishai, Ber, Beryl, Betzalel, Binyamin, Binyamin-Ze’ev, Bivi, Boaz

C:
Chacham , Chadad, Chagai, Chagi, Chanan, Chananel, Chananya, Chanoch, Chatzkel, Chaim, Cheifer, Chen, Chizkiyahu, Choni

D:
Dan, Daniel, David, Deror, Dov, Dubi

E:
Eden, Efrat, Efrayim, Ehud, Eichi, Eitan, Eizer, Eizik, Elazar, Elchanan, Elezri, Eli, Eliezer, Elimelech, Elinatan, Eliram, Eliran, Elisha, Elituv, Eliyahu, Elkana, Elkayam, Elyakim, Elyashiv, Emanuel, Erez, Even, Evenezer, Ezekiel, Ezer, Ezra

F:
Feivel, Fichel, Fishel

G:
Gabai, Gabbai , Gabi, Gabriel, Gad, Gafni, Gai, Gal, Gamliel, Gavriel, Gedalya, Gedalyahu, Gershon, Gever, Gidon, Gil, Gil–Ad, Gilad, Gili, Gur–Ari

H:
Henech, Hersh, Hershel, Herz, Hillel, Hosheia

I:
Iezer, Isaac, Israel, Issachar, Isser, Itamar

J:
Jacob, Jeremiah, Jesse, John, Jona, Jonah, Jonathan, Joseph, Joshua, Judah

K:
Kaduri, Kahana, Kalmon, Karmel, Karmeli, Karmiel, Katan, Katriel, Kehat, Kuti, Kutiel

L:
Label, Lazer, Leib, Leibel, Lemech, Lemel, Leor, Lev, Levi, Lezer, Li-Or, Leob

M:
Macabee, Maccabee , Maimon, Manasseh , Mannes , Manoach, Mashiach, Matanya., Matanyahu, Mati, Matitya, Matityahu, Matzliach, Mazal, Meigein, Meir, Meiri, Mei-Zahav, Melech, Menachem, Menashe, Mendel , Micha, Michael, Mordechai, Moshe

N:
Nachman, Nachmani , Nachmiel, Nachson, Nachum, Naftali, Natan, Nechemya, Nechum, Netanel, Netanya, Nissan, Nissim, Noach, Noam

O:
Oded, Ofir, Ohed, Oran, Oshiya

P:
Paseachs, Peretz, Pesach, Pesachya, Petuel, Pinchas

R:
Raanan, Rachaman, Rachamim, Rachmiel, Rachum, Rafi, Rani, Ranon, Raviv, Refael, Reuel, Reuven, Roni

S:
Saadya, Saba, Samson, Samuel, Sanser, Segel, Sender, Shabtai, Shachar, Shai, Shalom, Shammai, Shaul, Shaya, Shealtiel, Shebsel, Shem, Shemarya, Shemaryahu, Shemaya, Shemayahu, Shem-Tov, Shepsel, Sheraga , Shimi, Shimon, Shimshon, Shlomi, Shlomo , Shmarya, Shmerel, Shmiel, Shmuel, Shmulke, Shneur, Simcha, Sinai, Solomon

T:
Tamir, Tanchum, Tarfon, Tomer, Tov, Tovi, Toviel, Toviya, Tuviya, Tzachi, Tzefanya, Tzemach, Tzevi, Tzidkiya, Tzidkiyahu, Tziyon

U:
Udi, Uri, Uriel , Uzi, Uziel, Uziyahu

V:
Velvol, Volf

Y:
Yaakov, Yankel, Yechezkel, Yechiel, Yechizkiya, Yechizkiyahu , Yehochanan , Yehonatan, Yehoshua, Yehuda, Yekutiel, Yerachmiel, Yerucham, Yesarel, Yeshaya, Yeshayahu, Yeshua, Yirmeya, Yirmeyahu, Yisachar, Yisrael, Yitzchak, Yizrael, Yochanan, Yoel, Yona , Yonatan, Yoran, Yosef, Yosei

Z:
Zalman, Zalmen, Zalmon, Zecharya, Zecharyahu, Ze’ev, Zeide, Zimroni, Zohar, Zusa, Zushe, Zusman, Zusmann