cobweb: [14] A cobweb was originally literally a web woven by a cop, a Middle English word for ‘spider’. It was short for attercop ‘spider’, a compound of Old English origin which had largely died out by the 17th century. This seems to have meant literally ‘poison head’, from Old English ātōr ‘poison’ and coppe ‘head, top’ (a possible relative of English cob). It was revived by J R R Tolkien in The Hobbit 1937.
cobweb (n.)
early 14c., coppewebbe; the first element is Old English -coppe, in atorcoppe "spider," literally "poison-head" (see attercop). Spelling with -b- is from 16c., perhaps from cob. Cob as a stand-alone for "a spider" was an old word nearly dead even in dialects when J.R.R. Tolkien used it in "The Hobbit" (1937).
