The Taittirīya Shakha (Sanskrit, loosely meaning 'Branch or School of the sage Tittiri'), is a shakha (i.e. 'branch', 'school', or rescension) of the Krishna (black) Yajurveda. Most prevalent in South India, it consists of the Taittirīya Samhita ('TS'), Taittirīya Brahmana ('TB'), Taittirīya Aranyaka ('TA'), and Taittirīya Pratisakhya ('TP').
The 'Taittiriya Shakha' can be loosely translated as 'Branch or School of (the sage) Tittri' or 'Branch or School of Taittiriya' or 'School of the pupils of Tittiri'.
'Taittiriya' is derived from the name of the sage Taittiri (or Tittiri).
'Shakha' means 'branch' or 'school'.
According to Monier-Williams Sanskrit-English Dictionary, Taittiri was a pupil of Yaska (estimated 4th-5th century BCE). According to the Vishnu Purana, Yaska was in turn a pupil of Vaiśampáyana, (estimated 6th century BCE). Taittiri is also stated in the Mahabharata to have attended 'the Yaga [Vedic ritual sacrifice] conducted by Uparicaravasu'.
'Tittiri' also means 'partridge'. This meaning is worked into the account of the stated origin of the School of Tittri in the Vishnu Purana (Book 3, Chapter 5). Following a division between Brahmins at Mount Meru - including Vaiśampáyana (whose pupil, Tittiri, is attributed to the Krishna (black) Yajurveda) and Yajnavalkya (attributed to the Shukla (White) Yajurveda) - 'The other scholars of Vaiśampáyana, transforming themselves to partridges (Tittiri), picked up the texts which he [Yájnawalkya] had disgorged, and which from that circumstance were called Taittiríya'. This indicates both Yaska and Taittiri were pupils of Vaiśampáyana.
The translator, H.H. Wilson, states in his commentary to this chapter that 'the term Taittiríya is more rationally accounted for in the Anukramańí or index of the black Yajush [Krishna YajurVeda]. It is there said that Vaiśampáyana taught it to Yaska, who taught it to Tittiri, who also became a teacher; whence the term Taittiríya, for a grammatical rule explains it to mean, 'The Taittiríyas are those who read what was said or repeated by Tittiri'.