1) A wool-dyed cloth of superior quality, originally dark-brown in colour (OED).
1252 pro qualibet ulna viridi vel burneti xx denarios, Flasby
1346 supertunicam meam de burneto cum capucio, Easingwold
1391 j coopertorium de albo et de burneto, Lockton
1413-4 ‘And for 4 ells of cloth of burnet purchased for making one cape’, Selby. It was a popular name for an ox, probably as a colour: 1545 one yocke of oxen the one called Lemynge and the other Burnett, Conisbrough
1558 to my sonne ... an ox called burnett with halfe the plowghe geare, Burley
1570 two oxen called Meriman and Burnitt, Sproatley. Possibly the source also of the by-name and surname: 1234 John Burnet, Lofthouse.