Tianzhu is the historical Chinese name for India.
Tianzhu was also referred to as Wutianzhu (Chinese: [[wikt:五天竺|五天竺]], literal meaning is "Five Indias"), because there were five geographical regions in the Indian subcontinent known to the Chinese: Central, Eastern, Western, Northern, and Southern India.
Originally pronounced as l̥induk[1] or *qʰl'iːn tuɡ 天竺 in Old Chinese, it comes from the Chinese transliteration of unattested Old Persian diminutive *Hinduka-, which is from attested h-i-du-u-š (Hindu),[2] which is itself derived from the Proto-Indo-Iranian *síndʰuš, the etymon also of Sanskrit Sindhu, the native name of the Indus River. Persians travelling in northwest India (present-day Pakistani Sindh and Punjab) named the subcontinent after the river around the 6th century BC. Tianzhu is just one of several Chinese transliterations of Sindhu. Yuāndú[3] (Chinese: [[wikt:身毒|身毒]] OC n̥i[ŋ][d]ˤuk) appears in Sima Qian's Records of the Grand Historian and Tiandu (Chinese: [[wikt:天篤|天篤]]) is used in the Book of the Later Han.[4] Yintejia (Chinese: [[wikt:印特伽|印特伽]]) comes from the Kuchean Indaka, another transliteration of Hindu. The western terms of Hindu and India also ultimately derive from the same Persian concept.
A detailed account of Tianzhu is given in the "Xiyu Zhuan" (Record of the Western Regions) in the Hou Hanshu compiled by Fan Ye (398–445):
In Japan, Tianzhu was pronounced as Tenjiku. It is used in such works as the Japanese translation of Journey to the West.
In Korea, Tianzhu was pronounced as Cheonchuk. It is used in Wang ocheonchukguk jeon (An Account of Travel to the Five Indian Kingdoms), a travelogue by the 8th century Buddhist monk Hyecho from the Korean Kingdom of Silla.