The Proto-Indo-European word *terh₁-
Word *terh₁-
Meaning to pierce, to pierce by rubbing
See also Proto-Indo-European: *ter(i)- ‘to turn, to rub’
Proto-Indo-European: *treu(hₓ)- ‘to rub away, to wear away’
Proto-Indo-European: *térh₁trom~térh₁dhrom ‘auger’
Synonyms *dhelg-, *dhwer-, *gʷel-, *h₂/₃weg(h)-

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