The Proto-Indo-European word *(w)rep-
Word *(w)rep-
Meaning to turn, to incline
Synonyms *kʷel-, *(s)kerbʰ-, *swerbʰ-, *ter(i)-

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’, *gēu-, gǝu-, gū- ‘to bend, curl, a kind of vessel’, *ĝʰwel- ‘to bend’, *k̂lei- ‘to lean’, *leng- ‘to bend’, *lenk- ‘to divide, to bend, to traverse’