better vs fail

better

verb
  • To give advantage to; to support; to advance the interest of. 

  • To surpass in excellence; to exceed; to excel. 

  • Had better. 

  • To improve. 

  • To become better; to improve. 

noun
  • An entity, usually animate, deemed superior to another; one who has a claim to precedence; a superior. 

adj
  • Greater in amount or quantity 

adv
  • Greater or lesser (whichever is seen as more advantageous), in reference to value, distance, time, etc. 

  • Had better. 

fail

verb
  • To be wanting to, to be insufficient for, to disappoint, to desert; to disappoint one's expectations. 

  • Not to achieve a particular stated goal. (Usage note: The direct object of this word is usually an infinitive.) 

  • To become unable to meet one's engagements; especially, to be unable to pay one's debts or discharge one's business obligation; to become bankrupt or insolvent. 

  • To receive one or more non-passing grades in academic pursuits. 

  • To give a student a non-passing grade in an academic endeavour. 

  • To be wanting; to fall short; to be or become deficient in any measure or degree up to total absence. 

  • To neglect. 

  • To be unsuccessful. 

  • Of a machine, etc.: to cease to operate correctly. 

adj
  • Unsuccessful; inadequate; unacceptable in some way. 

noun
  • A failure, especially of a financial transaction (a termination of an action). 

  • A failure (condition of being unsuccessful). 

  • A failing grade in an academic examination. 

  • Poor quality; substandard workmanship. 

  • A failure (something incapable of success). 

  • A piece of turf cut from grassland. 

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