δημ-ωφελής · dēm-ōphelēs — LSJ
of public use, λόγοι Pl. Phdr. 227d; πολιτεύματα Plu. An seni 2.784d; δ. τι πραχθέν D.C. 72.7, cf. Luc. Bis Acc. 11; τὸ δ. the common good, Hdn. 2.3.8: Sup. τὸ -έστατον Ph. 2.177.
of persons, Democr. 282, Phld. Rh. 2.02 S.; ἡγεμών Plu. Sull. 30.
Adv. -λῶς CIG 4415b (Iotapata), IPE 12.39.36 (Olbia), IGRom. 4.860 (Laodicea ad Lycum): Sup. -έστατα D.C. 56.37.