writhe (v.) Look up writhe at Dictionary.com
Old English wriðan (transitive) "to twist or bend," earlier "to bind or fetter," from Proto-Germanic *writhanan (cognates: North Frisian wrial, Old High German ridan, Old Norse riða, Middle Swedish vriþa, Middle Danish vride), from PIE *wreit- "to turn, bend" (see wreath). Intransitive, of the body or limbs, "move in a twisting or tortuous manner," from c.1300. Related: Writhed; writhing.