1) Originally forest land, found in Old English place-names such as Easingwold. However, after the trees had been cleared it came to be used of open upland areas.
On record as a by-name from the thirteenth century: 1254 John de Wald, Fawdington
1322 Robert del Wald, York
1370 Adam del Wald, York. As a vocabulary item it has remained in use: 1590 the would was sevred into towe equall parts and halfe plughed one yer and halfe a nother yer, Kirby Underdale
1600 ‘that parcel of pasture called the great wold between le greate wowld and the demesne of Duglebye’
1619-21 the agistement of a spacious moorish wolde pasture grounde called Wheeledale, a verie colde and barreyne place, Goathland
1642 most of the grasse that groweth ... on the leyes of the wolds is a small, sparrie and dry grasse, Elmswell. It survived as a specific description of the upland region in the county which stretches from Humberside into north Yorkshire. This was referred to as Yorkeswold in 1472-5.
2) The plant <i>Reseda Luteola</i> which yields a yellow dye used by clothiers, known popularly as Dyers’ Rocket.
1755 vetches, rapes and Turnips with Wolds for the Dyers are frequently sown in Mirfield
1760 Wowlds for dyeing of yellow with are grown about Wakefild ... The farmers grows them so sells them att so much per hundred or by the stone to dyears. A South Crosland farmer recorded the purchase of Wouldwood seed and would seed sowing in 1815. One possible earlier example has been noted: 1390 et ij stane wald, York. These spellings were usual locally but ‘weld’ is the OED headword.