出典:Wiktionary
From wither- + shins, sins, alteration of withersuns (“contrary to the sun's course”, literally “against the sun's”), modelled after Middle Low German weddersins, weddersinnes (“in the opposite direction”), from Middle High German widdersinnes (“in the opposite direction”, literally “contrary to reason”), from wider (“opposite”) + sinnes, genitive of sin (“course”). Compare also 古期英語 wiþersīenes (“backwards, withershins”), Icelandic viðer (“against”), Danish veder, Swedish veder. More at wither, sense.
withershins (not comparable)