Opella, Aliud diminutiuum. Horat. Little labour.Parua opella. Lucret. Operárius operárij, m. g. Varro. A Labourer: a Workeman.Parandi sunt operarij qui laborem ferre possint. Varro. Appositus ad deferenda quædam onera operarius.Cic.
Lewis and Short: Latin dictionary
ŏpella, ae, f.dim. [opera], little or light pains, labor, service (poet.): parva, Lucr. 1, 1114: forensis, Hor. Ep. 1, 7, 8.