thirdings

from the GNU version of the Collaborative International Dictionary of English.

• noun plural (Eng. Law) The third part of the corn or grain growing on the ground at the tenant's death, due to the lord for a heriot, as within the manor of Turfat in Herefordshire.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun UK, law One third of the corn or grain growing on the ground at the tenant's death, paid to the lord as a heriot.