single-phase adjective 1verb 1forms 3 adjective1 •Using an alternating current in which all voltages supplied are in the same phase.The four traction motors are connected permanently in parallel. They are six-pole series wound machines specially developed for operation on a rectified 50-cycle single-phase supply. — 1960 verb1 •To use such a current. formssingle-phased · single-phasing · single-phases