"spider," Old English atorcoppe "spider," literally "poison-head," from ator "poison, venom" (Middle English atter), from Proto-Germanic *aitra- "poisonous ulcer" (source also of 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" (compare 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]
It lingered in Northern England dialect in the sense "peevish, ill-natured person" (c. 1500).