What Is A Cobweb?

Cobweb is the Middle English term for a spider web. In etymology, it is derived from the word 'coppe' which means spider. In modern day usage, however a cobweb is often used to describe an old web with no spider in it. A cobweb is an intricately entwined web of spider silk threads. It is built over a period of time by a spider, often with the intention of using its sticky texture as a means of trapping prey. Nevertheless, it must be noted that not all spiders build cobwebs to capture prey and not all spiders build webs in the first place. There are several varieties of spider webs including spiral orb webs, tangle webs, funnel webs, tubular webs and sheet webs.

In addition, Cobweb is also the name of sensual comic book heroine. Although she was markedly lacking in powers of a lethal nature, she effectively employed her considerable seductive allure to do away with any opposition she may have encountered.

Cobweb is also the name of a novel by renowned writer Stephen Bury.

In economics, a cobweb model is an economic model that depicts the cycle of supply and demand.

It's an old spider web

The word cobweb can be used for the kind of spider web that is full of dirt and the spider has left the web for another place. But why the word is being used as such is yet to be decided but the probability of the use of the word can certainly be determined.

Cob is a word that can trace its derivation in the Middle English and was used to signify a spider. As the word cob is no longer in use to describe a spider the web that is no longer inhabited by a spider can be called a cobweb.

But this explanation is also not very perfect and it can be called just a speculation not the exact answer of the phenomenon that can described in your question. But is has been taken as an answer because no other alternative is available that can confirm the use.