power supply vs virtue

power supply

noun
  • Used other than figuratively or idiomatically: see power, supply. 

  • A source of power such as the mains or a generator. 

  • That part of a piece of electronic apparatus that provides appropriate voltages for the rest of the electronics from the connected AC source. 

virtue

noun
  • The inherent power or efficacy of something (now only in phrases). 

  • A creature embodying divine power, specifically one of the orders of heavenly beings, traditionally ranked above angels and below archangels. 

  • Accordance with moral principles; conformity of behaviour or thought with the strictures of morality; good moral conduct. 

  • A particular manifestation of moral excellence in a person; an admirable quality. 

  • Specifically, each of several qualities held to be particularly important, including the four cardinal virtues, the three theological virtues, or the seven virtues opposed to the seven deadly sins. 

  • An inherently advantageous or excellent quality of something or someone; a favourable point, an advantage. 

  • Specifically, moral conduct in sexual behaviour, especially of women; chastity. 

How often have the words power supply and virtue occurred in a corpus of books? (source: Google Ngram Viewer )