Standard empty weight

The weight of the airframe, engines, all permanently installed equipment, and unusable fuel. Depending upon the part of the Federal regulations under which the aircraft was certificated, either the undrainable oil or full reservoir of oil is included.

Aviation Maintenance Technician Handbook — General, p. G-10

Also defined in 2 more sources

(GAMA) The weight of a standard airplane including unusable fuel, full operating fluids, and full oil.

Aircraft Weight and Balance Handbook, p. G-4

This weight consists of the airframe, engines, and all items of operating equipment that have fixed locations and are permanently installed in the airplane including fixed ballast, hydraulic fluid, unusable fuel, and full engine oil.

Pilot's Handbook of Aeronautical Knowledge, p. G-28