Around the beginning of the 20th century, archaeologists recovered a number of manuscripts from oases in the Tarim Basin written in two closely related but previously unknown Indo-European languages.
Another text recovered from the same area, a Buddhist work in Old Turkic, included a colophon stating that the text had been translated from Sanskrit via a toxrï language, which Friedrich W. K. Müller guessed was one of the newly discovered languages.
Müller called the languages "Tocharian" (German Tocharisch), linking this toxrï with the ethnonym Tókharoi (Ancient Greek: Τόχαροι, Ptolemy VI, 11, 6, 2nd century AD) applied by Strabo to one of the Scythian tribes that overran the Greco-Bactrian kingdom (present day Afghanistan-Pakistan) in the second half of the 2nd century BC.[a]
This term was itself derived from Indo-Iranian (cf. Old Persian tuxāri-, Khotanese ttahvāra, and Sanskrit tukhāra), the source of the term "Tokharistan" usually referring to 1st millennium Bactria, as well as the Takhar province of Afghanistan. The Tókharoi are often identified by modern scholars with the Yuezhi of Chinese historical accounts, who founded the Kushan Empire. These people are now known to have spoken Bactrian, an Eastern Iranian language that is quite distinct from the Tocharian languages, and Müller's identification is now a minority position among scholars. Nevertheless, "Tocharian" remains the standard term for the languages of the Tarim Basin manuscripts and for the people who produced them.
The name of Kucha in Tocharian B was Kuśi, with adjectival form kuśiññe. The word may be derived from Proto-Indo-European *keuk "shining, white".
The Tocharian B word akeññe may have referred to people of Agni, with a derivation meaning "borderers, marchers".
One of the Tocharian A texts has ārśi-käntwā as a name for their own language, so that ārśi may have meant "Agnean", though "monk" is also possible.