1) This was a sea-going boat in earlier times. However, most Yorkshire references are later and point to it as the name of a small vessel, one that was used on the inland waterways or towed behind a larger vessel. In some respects it may have been used interchangeably with cock or cock-boat.
1333 qd navem suum vocatam la Saynte Marie cogge de Ravensrodd. In some respects it may have been used interchangeable with cock or cock-boat: 1457 Lego ... 1 naviculum vocatam le Showte... 1 cogship, York
1475 Willelmi Gleson, cogg de Selby, xijd, York
1683 all that sixteenth parte of the Keell knowen by the name Caire-for-all ... & the sixteenth parte of the Cogg boate, Selby.
2) To plough for the purpose of breaking up the clods and making the ground smoother and finer (EDD).
The cogging harrow was for breaking up rough fallows: 1755 lower Intac ... Fallowing of Seven [acres] Plowings and Coggings at 6s per plowing ... for two acres 1s - Ł4 4 0.