By Swami Harshananda
Pratihāra literally means a part of the sāman, introduced with the chant huiii.
The udgātṛ is one of the four principal priests in a Vedic sacrifice representing the Sāmaveda. He sings the sāmans at the appropriate stages in a sacrifice. He has three assistants one of whom is the pratihartṛ or pratihartā. It is his duty to chant the pratihāra. The pratihāra is a reply or response to prastāva, the first part of a sāman.
- The Concise Encyclopedia of Hinduism, Swami Harshananda, Ram Krishna Math, Bangalore