Vadim

Origin: Russian

Meaning: it’s the Russian form of Bademus, a Latinized form of a Persian name, meaning unknown. It’s also been linked to Slavic Vadimir meaning “accuse + peace, world” from Slavic elements vaditi (accuse, to slander, to blame) and miru (peace, world).

Vadik is a diminutive form of the name.

Variants: Vadym (Ukrainian); Vadzim (Belarusian)

Sorin

Origin: Romanian, French, Jewish, Russian, Japanese

Meaning: possibly from Romanian soare meaning “sun”.

I’ve also seen it as a surname. It could be French in origin, from Old French sor, a diminutive of Sorel, meaning “chestnut”, originally a nickname for someone with reddish hair.

It also has a different etymology, a Jewish surname derived from a metronymic of Yiddish female personal given  name Sore, from Hebrew name Sara meaning “princess”, with the Slavic suffic -in. From what I could find, it seems to be (or used to be) very popular in Russia, especially Belarus.

Sōrin (宗 麟)also seems to be a Japanese masculine given name, such as Ōtomo Sōrin (who also went by other names), who was a daimyo of the Ōtomo clan in the 16th century (1530-1587). I couldn’t find any meaning on his name, though sōrin is also the vertical shaft on top of a Japanese pagoda, usually made out of bronze or stone. It means “alternate rings” with the kanji used (相 輪).

Sorinel is a pet form of the name.

Sorina is the feminine form of the name.

Larissa, Larisa

Origin: Greek

Лариса (Russian, Ukrainian) Larisa

Λαρισα (Ancient Greek) Larisa

Meaning: the name of an ancient city in Greece, the name most likely means “citadel” or “fortress”.

Larissa is a nymph in Greek mythology.

Lara is a short form of the name.

Variants: Larysa (Ukrainian); Larisa is the version often used in Russia.

Tatiana

Origin: Latin

Meaning: the feminine form of Tatianus, a derivative of Tatius, of unknown meaning.

Tatiana is a name mentioned once in Book 4 (The Miserable Mill), as a friend of the author Lemony Snicket.

Tanya/Tania is a short form of the name.

Variants: Tatyana (Russian); Tatjana (Finnish, German), Tatianna, Tatyanna (English); Tatianus (m); Tatienne (French)

Ilya, Ilia

Origin: Russian, Bulgarian, Georgian

Илья (Russian)

ილია (Georgian)

Илия (Bulgarian)

Meaning: Ilya is the Russian form of Elijah meaning “My God is Yahweh”.

Ilia is also a variant transcription of Ilya, but it’s also the Georgian form of Elijah or also a variant transcription of Bulgarian Iliya (also the Bulgarian form of Elijah)

Ilyusha and Ilyushenka are diminutive forms of Ilya

Yuri

Origin: Russian, Ukrainian, Japanese, Korean

Meaning: farmer, earthworker; lily; glass

Yuri is a male Russian name, a variant transcription Yuriy, which is the Russian and Ukrainian form of George, meaning “farmer, earthworker”.

( Юрий ) Russian;  ( Юрій ) Ukrainian

Yuri is also a Japanese female name meaning “lily” (百合).. Yuriko (百合子) is a variant of the name, meaning “lily child”

It’s also a Korean female name spelled Yu-ri, Yoo-ri, or You-ri, and has various meanings depending on the hanja used. One such meaning I found online is “glass”  ( 유리 )

Vladimir, Vladimír

Origin: Slavic

Владимир (Russian, Serbian, Bulgarian, Macedonian)

Meaning: from Slavic elements vladeti “rule” and meru “great, famous” meaning “famous ruler”. According to Behindthename, the second element could also be associated with miru “peace, world” so the meaning could also be “peaceful ruler” or “world ruler”. The Vladimír spelling is the Czech and Slovak form of Vladimir.

Roma

Рома (Russian)

Origin: Russian, Italian

Meaning: In Russian, it’s a diminutive form of the name Roman, which comes from Latin Romanus meaning “Roman”. It’s also the Italian name of the city of Rome; in ancient Roman mythology, Roma was the female personification of the city

Milan

Origin: Slavic

Милан (Russian, Serbian, Bulgarian, Macedonian)

Meaning: from Slavic element milu meaning :gracious, dear”. According to Wikipedia, it also has Indian and Latin origins; in Hindu it’s supposed to mean “eager”, “worthy”, or “competitor”, all coming from an expression meaning “a coming together”. In Latin, it’s supposed to mean “eager and laborious”

In Slavic-speaking countries, Milan is strictly a male name with Milana or Milena as its feminine counterparts, although it’s also been used for girls, probably inspired by the city in Italy (whose name comes from a different source- either from Latin or Celtic roots)