1) Land by a river (OED), or a precipitous slope (PNWR7/242). Research by David Shore suggests that it was more accurately ‘an arc of rising land above a river or stream’.
In several cases a highway passed down the ‘shore’ to a river crossing, as at Shore in Huddersfield. It occurs several times as an element in minor place-names, and occasionally as a vocabulary item: 1456 quandam parcel terr. juxta ripam aque prope Thwongesbrigg sub le shore, Netherthong.
2) A regional spelling of ‘sewer’.
1664 A man about Ealand went to the Colepit on Monday last, fel to drinking and as he came home ... fel down a shore and brake his neck
1766 There hath been and still is a common Shore in the Township of Wakefield called Skiterick, in the King’s Common Highway ... leading from Sandal to Stanley .