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