1) A channel conducting water from a mill.
The most explicit reference to this word is in a document for Hunsworth in the parish of Birstall. Permission was granted in 1788 for the erection of a fulling mill and a house for the miller, and one of the tenant’s obligations was to make a wash or Byset for conveying spare or surplus water from the goit or dam into the brooke . The term evidently had the same meaning as ‘by-wash’, recorded once only in the OED, in 1885. In fact ‘by-set’ is on record from the 1700s in documents that had to do with mills, e.g. 1794 goits, cuts, bysets, shuttles, etc, Mytholmbridge. In 1782, the Honley overseers of the highways recorded getting stones from a place cauld By Set or water corce betwixt Farnley and Honley and this hints at the word giving rise to a local place-name. In fact the earliest reference that I have noted is on the estate map of Huddersfield for 1716 where Bysett Close is the name of a field located between the goit of Paddock Mill and the River Colne.