1) Of uncertain meaning, maybe assart land incorporated into the town fields or a regional alternative to 'foreland'.
The OED found this term only in Yorkshire and gave two examples, the earliest in Ryton in 1510. It is actually frequent in the North and East Ridings in the sixteenth century, and an abstract of Guisborough manor in 1539 has Forbylande listed under Marske and Rotsey. References elsewhere include: 1562 ‘a parcel of forbye land’, Hackness
1619-21 He that holdeth a mesuage, a cottage or forby lande … is to dowble his free rente for one yeare, Pickering. In this Pickering example such tenants were contrasted with those whose holding consisted of oxgangs, and similar East Riding references were quoted and commented on by Jennifer Kaner: 1575 Item to James Freman for rent of certayne forby lande iis vid, South Cave
1578 the said tenement with all the forby land … lying in the towne fieldes, South Cave. She considered it to be assart land that had been incorporated into the town fields, measured in acres not oxgangs, and possibly a regional alternative to ‘foreland’.