This is what we call fibres that come from the first shearing of a sheep or lamb. They have been neither spun nor felted nor part of any other finished product, and contain no more than 0.3% of impurities.
The term denotes a type of sleeve that starts at the collar and joins the underarm. Wider than a conventional sleeve, it was invented by Lord Raglan, a British officer who lost his arm during the battle of Waterloo and wanted to put his coat on without constraint. The chic man in a hurry has him to thank.