One theory is Tenugu is derived from the Proto-Dravidian word "ten", meaning "south" to signify "The people who live in the South". This seems likely because there are similar names for other Dravidian languages : Badaga, Kodagu, and Vadugar (a name for the Telugu-speaking people given by people in Tamil Nadu, meaning "people who are in the north (relatively)"). The name Telugu then, is a result of the 'n' -> 'l' alternation established in Telugu. Other variants used include Telengu, Telungu, and Tenungu, one of which could have lent its name to the region Telangana.
Alternatively, the name Telangana could have been derived from the word "trilinga", as in the "trilinga desha", which translates to "the country of the three Lingas". According to a Hindu legend, Shiva descended in the lingam form on three mountains, Kaleshwaram, Srisailam and Draksharam, which marked the boundaries of the Trilingadesha, later called "telinga", "telunga" or "telugu". The word "telinga" changed over time to Telangana and the name Telangana was designated to distinguish the predominantly Telugu-speaking region of the erstwhile Hyderabad State from its predominantly Marathi-speaking one, Marathwada. One of the earliest uses of a word similar to Telangana can also be seen in a name of Malik Maqbul (14th century C.E.), who was called the "tilangani", which implies that he was from Telangana. He was the commander of the Warangal Fort (Kataka Paludu).