The Collaborative International Dictionary of English v.0.48:

Folkland \Folk"land`\, n. [AS. folcland.] (O.Eng. Law)
   Land held in villenage, being distributed among the folk, or
   people, at the pleasure of the lord of the manor, and resumed
   at his discretion. Not being held by any assurance in
   writing, it was opposed to bookland or charter land, which
   was held by deed. --Mozley & W. Folklore

Bouvier's Law Dictionary, Revised 6th Ed (1856):

FOLK-LAND, Eng. law. Land formerly held at the pleasure of the lord, and
resumed at his discretion. It was held in villeinage. 2 Bl. Com. 90.