1) A cloth or curtain to put in front of a window.
2) A winnowing cloth or sheet.
1377 j window clath, Hackness
1402 unum Wyndncloth [sic] et unum malt arke, Normanton
1460 j cart load of hay ... j wyndowcloth, Sharow
1567 14 seckes & one windowe clothe, Fixby
1612 7 sacks and a windowcloth, Eccleshill
1691 1 fann, 2 windowing clothes 6s 6d, Selby.