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• 新羅

First attested in the Records of the Three Kingdoms (c. 290 CE) as 斯盧 / 斯卢 (OC *se b·raː, MC siᴇ luo) as in 斯盧國 (“Saro state”), one of the 12 statelets belonging to the Jinhan confederacy. Other old variations include 新盧 / 新卢 (OC *siŋ b·raː, MC siɪn luo) and 斯羅 / 斯罗 (OC *se raːl, MC siᴇ lɑ).

In Old Korean documents, those country names were equated with the name of the capital, 徐羅伐 (Syerapel, “Seorabeol”, modern Gyeongju), a compound of 徐羅 (syera) + 伐 (pel, “village”). Other variants include 徐那伐 (syenapel), 徐耶伐 (syeyapel) and 徐伐 (syepel), whence 서울 (seoul, “capital city”).

徐 (sye), the first syllable of 徐羅 is considered to mean “gold” because of 금성 (金城, geumseong, “gold castle/city/fort”), the sinicized name of the capital city (cf. 쇠 (soe), “iron, metal”). The second syllable 羅 (ra) is according to one theory a connective particle, but another theory posits that it means “land”.

新羅

1. Silla (an ancient kingdom in modern Korea, one of the Three Kingdoms, existing from 57 BCE to 935 C.E.; at its maximum covering all of modern South Korea and most of modern North Korea)

• 百濟／百济 (Bǎijì)
• 高句麗／高句丽 (Gāogōulí)

新羅

1. (～區) Xinluo (a district of Longyan, Fujian, China)

Japanese Wikipedia has an article on:

新羅

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Silla

Wikipedia

⟨siraki₂⟩ → */sirakɨ/ → /ɕiraɡi/

Shift from Old Japanese 新羅 (Siraki₂).

• (Tokyo) しらぎ (Atamadaka – )
• IPA^(key):

新羅(しらぎ) • (Shiragi) 

1. Silla (an ancient kingdom in modern Korea, one of the Three Kingdoms, existing from 57 BCE to 935 C.E.; at its maximum covering all of modern South Korea and most of modern North Korea)

• 百済(くだら) (Kudara)
• 高麗(こま) (Koma)

• 新羅(しらぎ)楽(がく) (Shiragi-gaku)
• 新羅(しらぎ)琴(ごと) (Shiragi-goto, “Silla koto”)
• 新羅(しらぎ)船(ぶね) (Shiragi-bune)

From the Middle Chinese-derived reading of the kanji characters.

• (Tokyo) しんら (Atamadaka – )
• IPA^(key):

新(しん)羅(ら) • (Shinra) 

1. Silla (an ancient kingdom in modern Korea, one of the Three Kingdoms, existing from 57 BCE to 935 C.E.; at its maximum covering all of modern South Korea and most of modern North Korea)

• 百(ひゃく)済(さい) (Hyakusai)
• 高(こう)麗(らい) (Kōrai), 高(こう)句(く)麗(り) (Kōkuri)

• 新(しん)羅(ら)三(さぶ)郎(ろう) (Shinra Saburō)

新羅 • (Silla) (hangeul 신라)

1. hanja form^? of 신라 (“Silla”) : Silla (an ancient kingdom in modern Korea, one of the Three Kingdoms, existing from 57 BCE to 935 C.E.; at its maximum covering all of modern South Korea and most of modern North Korea)

Shiratori (1896) derived this word from Old Korean 徐羅城 (*Syera-KUY), reconstructed from 徐羅 (syera) as in 徐羅伐 (Syerapel, “Seorabeol”, its capital city, present day Gyeongju) or 斯羅 (MC sje la), an older name of Silla; and Old Japanese 城 (ki₂, “fortress, castle”) considered as borrowed from Baekje 己 (kuy), from Goguryeo 忽 (kol(o)) and older form 溝婁 / 沟娄 (kwurwu, OC *koː ɡ·roː/ɡ·ro, MC kəu lɨo|ləu), equated with Old Korean 伐 (pel, “village”).

Aisin-Gioro (2009) proposed that there are also similar exonyms for Korea, made from the same configuration, Old Turkic 𐰲𐰇𐰞𐰍𐰞 (čölüg el, “Silla”), Jurchen solgor (“Goryeo”, whence cognate with Manchu ᠰᠣᠯᡥᠣ (solho), “Korea”), and borrowed as Mongolian Солго (Solgo, “Korea”) and Middle Mongol 莎郎合思 (Solangqas, “Goryeo”, whence cognate with Mongolian Солонгос (Solongos), “Korea”), as being related to *Syera-kuy, and Khitan 𘬥𘲀𘭲𘮒 (*ś ul ó úr, “Silla, Goryeo”) as a descendant of 徐羅伐 (Syera-pel).

新羅 (Siraki₂) (kana しらき)

1. Silla (an ancient kingdom in modern Korea, one of the Three Kingdoms, existing from 57 BCE to 935 C.E.; at its maximum covering all of modern South Korea and most of modern North Korea)
   • c. 759, Man’yōshū, book 15, poem 3696:

     新羅奇敞可伊敞爾可加反流由吉能之麻由加牟多登伎毛於毛比可禰都母

     Siraki₂-pe₁ ka ipe₁ ni ka kape₁ru Yuki₁-no₂-sima yukamu tado₂ki₁ mo omopi₁kanetu mo

     Returning to my house in Silla, I still have no clue about whether I should depart from the island of Yuki.

• 高句麗 (Ko₂ma, “Goguryeo”)
• 百濟 (Kudara, “Baekje”)

• Japanese: 新羅 (Shiragi)

新羅

1. chữ Hán form of Tân La (“Silla”): Silla (an ancient kingdom in modern Korea, one of the Three Kingdoms, existing from 57 BCE to 935 C.E.; at its maximum covering all of modern South Korea and most of modern North Korea)