structural:scholar_edition, structural:expansion, quality:correction
Name

The oldest form of the name is recorded in Chinese annals from the 4th century BC, describing the beliefs of the Xiongnu. It takes the form 撑犁/ Cheng-li, which is hypothesized to be a Chinese transcription of Tängri. (The Proto-Turkic form of the word has been reconstructed as *Teŋri or *Taŋrɨ.) Alternatively, a reconstructed Altaic etymology from *T`aŋgiri ("oath" or "god") would emphasize the god's divinity rather than his domain over the sky. It is generally assumed the term tengri originally meant "sky". Andrey Kononov suggested that the term is formed by the words tän (morning) and injir (evening) into tänri, referring to the sky as whole.

The Turkic form, Tengri, is attested in the 8th century Orkhon inscriptions as the Old Turkic form 𐱅𐰭𐰼𐰃 Teŋri. In modern Turkish, the derived word " Tanrı " is used as the generic word for "god", or for the Abrahamic God, and is used today by Turkish people to refer to any god. The supreme deity of the traditional religion of the Chuvash is Tură.

Other reflexes of the name in modern languages include Mongolian: Тэнгэр ("sky"), Bulgarian: Тангра, Azerbaijani: Tanrı.

Earlier, the Chinese word for "sky" 天 (Mandarin: tiān < Old Chinese * thīn or * thîn) had been suggested to be related to Tengri, possibly a loan into Chinese from a prehistoric Central Asian language. However, this proposal is unlikely in light of recent reconstructions of the Old Chinese pronunciation of the character "天", such as * qʰl'iːn (Zhengzhang) or * l̥ˤi (Baxter-Sagart), which propose for 天 a voiceless lateral onset, either a cluster or single consonant, respectively. Baxter & Sagart (2014:113-114) pointed to attested dialectal differences in Eastern Han Chinese, the use of 天 as a phonetic component in phono-semantic compound Chinese characters, and the choice of 天 to transcribe foreign syllables, all of which prompted them to conclude that, around 200 CE, 天's onset had two pronunciations: coronal * tʰ & dorsal * x, both of which likely originated from an earlier voiceless lateral * l̥ˤ.

Linguist Stefan Georg has proposed that the Turkic word ultimately originates as a loanword from Proto-Yeniseian *tɨŋgɨr- "high".

Amy Chua renders the name as "he Eternal Blue Sky", likely because of the connotations of the name's usage.