text: Another form of this root means "to flow, to move near by flowing". (All the meanings and derivations cited above are based upon Sanskrit English Dictionary of Monier-Williams). Monier-Williams also quotes Tārānātha who compiled the great (Sanskrit-to-Sanskrit) dictionary named "ṛṣati jñānena saṃsāra-pāram" (i.e., "one who reaches beyond this mundane world by means of spiritual knowledge").
  Before Monier-Williams' work was published, Yāska  suggested it came from "drish" and quotes Aupamanyava to support his opinion.
  However, the root has a close Avestan cognate ərəšiš "an ecstatic" (see also Yurodivy, Vates). Yet the Indo-European dictionary of Julius Pokorny connects the word to a PIE root  meaning "rise, protrude", in the sense of "excellent" and thus cognate with Ṛta and right and Asha. In Sanskrit, forms of the root rish become arsh- in many words, (e.g., arsh)
  Modern etymological explanations such as by Manfred Mayrhofer in his Etymological Dictionary leave the case open, and do not prefer a connection to  "pour, flow" (PIE ), rather one with German rasen "to be ecstatic, be in a different state of mind" (and perhaps Lithuanian aršus).
  In Hindu texts
  In the Vedas, the word denotes an inspired poet of Vedic hymns. In particular, Ṛṣi refers to the authors of the hymns of the Rigveda. Some of the earliest lists of Rishi are found in Jaiminiya Brahmana verse 2.218 and Brihadaranyaka Upanishad verse 2.2.4.