Latin, gersuma.

The gersuma was a customary payment made by the peasantry to the lord of the manor in addition to their rents and renders. It appears to be similar to the exaction (tailla) paid in Lincolnshire.

For more detail, see Paul Vinogradoff, English society in the eleventh century: essays in English medieval history (1908).

See also exaction, farmer, and codes for miscellaneous items.