Lewis & Short

Văcūna, ae, f. [vacuus, II. A.], the goddess of rural leisure, esp. honored by the Sabines, Hor. Ep. 1, 10, 49 Acr.; Ov. F. 6, 307; Plin. 3, 12, 17, § 109; Aus. Ep. 4, 98.
Hence, Văcūnālis, e, adj., of or belonging to Vacuna: foci, Ov. F. 6, 308.