unit of land area equal to 30 acres
• (n.) A measure of land of uncertain quantity, varying from fifteen to forty acres; a virgate.
Yard'land` noun (O. Eng. Law) A measure of land of uncertain quantity, varying from fifteen to forty acres; a virgate. [ Obsolete] 
a quarter of a HIDE.
In old English law, a yardland was a measure of land of uncertain quantity, varying from fifteen to forty acres.