The Collaborative International Dictionary of English v.0.48:
Yardland \Yard"land`\ (y[aum]rd"l[a^]nd`), n. (O. Eng. Law) A measure of land of uncertain quantity, varying from fifteen to forty acres; a virgate. [Obs.] [1913 Webster]Bouvier's Law Dictionary, Revised 6th Ed (1856):
YARDLAND, old Eng. law. A quantity of land containing twenty acres. Co. Litt. 69 a.