周しゅう波は数すう利り用よう効こう率りつMeaningsNoun1. spectral efficiencyKanji used周circumference波a wave数number利profit用used for効be effective率ratioComposed of周しゅう波は数すうfrequency (esp. of waveforms)Noun利り用ようuse; utilization; utilisation; applicationNoun効こう率りつefficiencyNoun