withy – ивовый прут, лоза, см. «willow», «wind»

withy (n.) (староанглийское «wiðig» - ива, ивовая ветка); из протогерманского *with- ива; из PIE корня *wei- (1) – закручивать, заворачивать
Old English wiðig "willow, willow twig," from Proto-Germanic *with- "willow" (source also of Old Norse viðir, Danish vidje, Swedish vide, Old High German wida, German Weide "willow"), from PIE root *wei- (1) "to bend, twist" (source also of Avestan vaeiti- "osier," Greek itea "willow," Latin vitis "vine," Lithuanian vytis "willow twig," Polish witwa, Welsh gwden "willow," Russian vitvina "branch, bough").

1675:
WITHY (ƿiðiᵹ, Sax.) – дерево, лоза (вился - лоза – «osier» - ЛЗ – (L) S); (1826): WITHE – ветка, ива, лоза, вязь, виток (“coil” = коло); G. “vidior”; P. “bed”; Swed. “wide”; D. “wedie”; T. “weide”; B. “wede”; S. “withthe”, L. “vitis”; WITHY – ива, лоза, ветка; S. “withig”

1) Вить, виться – ВТС – VTS (WTHTH) (WD)
2) Ветка – ВТК – WTK - WTH