"spider," Old English attorcoppe, literally "poison-head," from ator "poison, venom," from Proto-Germanic *aitra- "poisonous ulcer" (cf. Old Norse eitr, Old High German eitar "poison;" German eiter "pus," Old High German eiz "abscess, boil;" Old English atorcræft "art of poisoning") + copp "top, summit, round head," probably also "spider" (cf. cobweb and Dutch spinne-cop "spider").
Amptes & attircoppes & suche oþer þat ben euere bisy ben maide to schewe man ensaumple of stodye & labour. [Elucidarium of Honorius of Autun (Wycliffite version) c.1400]