The Proto-Indo-European word *reik-
Word *reik-
Meaning line, scratch
See also Proto-Indo-European: *rei- ‘scratch’
Synonyms *h₄erh₂os, *kars-, *(s)grebʰ-, *skebʰ-

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

Other words that might be of interest
*peik̂- ‘paint, mark’