'unwholesome', 

are all those karmic volitions (kamma-cetanā; s. cetanā) and the consciousness and mental concomitants associated therewith, which are accompanied either by greed (lobha) or hate (dosa) or merely delusion (moha); and all these phenomena are causes of unfavourable karma-results and contain the seeds of unhappy destiny or rebirth. 

Cf. karma, paticca-samuppāda (1), Tab. II.