The Proto-Indo-European word *néh₁tr-~nh₁tr-
Word *néh₁tr-~nh₁tr-
Meaning snake
See also Proto-Indo-European: *(s)neh₁- ‘twist, turn’
Synonyms *neh₁tr-, *h₁ógʷhis, *hₐéngʷhis

Comments
Mallory J.P. and Adams D. (2006)

Other words that might be of interest
*ank-2, ang- ‘to bend, bow, curve, snake coil, anchor’