A mish-mash of things you come accross while researching.
Historically, the Welsh had a patronymic naming system a bit like the Scandinavians. In the same way that Scandinavians suffix 'son' to a name, the Welsh prefixed ab or ap (meaning son of) to a name. In Scandinavia, Richard's son becomes Richardson. In Wales it would be Ap Richard... or Prichard.
As fixed surnames became more mainstream, the Welsh were left with a relatively small pool of surnames, which must have led to some confusion. This is probably the reason that surnames were combined with other identifying facts about an individual: their mother's name, where they live, or their job.
Those of my era will remember 'Jones the Steam', and the Newsagent in Holywell was called 'Morris the Observer'. In our family one of the maternal names stuck.
A delver was someone who dug things up. In Yorkshire, most often it refers to someone who worked in a stone quarry. The term is applied to both someone who weilds a shovel and someone who owns a quarry so we have to look closely to see what social 'strata' an individual comes from.
James Clegg is our most prominent delver but there are several in our tree.
Locally around the Calder Valley the word Delph - an old English word for a quarry - occurs in several place names. The extended family of James Clegg's second wife, Elizabeth Spencer, lived at Delph Hill near King Cross, Halifax and were stone merchants (delvers).
Preparing and spinning yarn is a complex process, but here's an attempt to explain the difference between woolen and worsted yarn. In short, it's to do with:
Wool used for worsted yarn has longer fibres. Generally longer than 5cm whereas woolen yarn can me made from shorter or long fibres or a mix. Having said that, worsted botany yarns are made from merino wool and the fibres for this can be shorter.
Woolen yarns are prepared by carding the wool. This separates out the fibres but leaves them still jumbled up in a kind of mesh. Worsted yarns are carded and then combed as well. This aligns all the fibres in one direction and gets rid of the short and damaged ones.
Finally, when the wool is spun, worsted yarn is spun more tightly than woolen yarn which makes it smoother and stronger.
Huddersfield Textiles explain it better and in more detail.