attrition vs regret

attrition

noun
  • The loss of participants during an experiment. 

  • A gradual, natural reduction in membership or personnel, as through retirement, resignation, or death. 

  • Grinding down or wearing away by friction. 

  • Imperfect contrition or remorse. 

  • The gradual reduction in a tangible or intangible resource due to causes that are passive and do not involve productive use of the resource. 

  • The wearing of teeth due to their grinding. 

  • The loss of a first or second language or a portion of that language. 

verb
  • To reduce the number of (jobs or workers) by not hiring new employees to fill positions that become vacant (often with out). 

  • To undergo a reduction in number. 

  • To grind or wear down through friction. 

regret

noun
  • The amount of avoidable loss that results from choosing the wrong action. 

  • Emotional pain on account of something done or experienced in the past, with a wish that it had been different; a looking back with dissatisfaction or with longing. 

verb
  • To feel sorry about (a thing that has or has not happened), afterthink: to wish that a thing had not happened, that something else had happened instead. 

  • To feel sorry about (any thing). 

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