Writhe comes from Old English wrīþan ('to twist, bind'), from Proto-Germanic *wrīþaną ('to twist'), from Proto-Indo-European *wreyt- ('to turn'). In current use it is a verb meaning "to twist or squirm, especially in pain or discomfort". That sense is explained by the older material without requiring a speculative semantic step: the inherited or borrowed base supplies the field of meaning, while the English formation fixes its modern role. The history is mainly one of transmission into English, with the older form and sense carried through borrowing or adaptation. The historical chain includes Old English wrīþan, Proto-Germanic *wrīþaną, and Proto-Indo-European *wreyt-. Related English forms include wreath, wreathe, wrist, and wroth. A derived form is writhing. For dictionary purposes, the important point is the continuity between the older form, the route into English, and the present lexical sense.