erratic vs random

erratic

adj
  • Deviating from normal opinions or actions; eccentric; odd. 

  • Unsteady, random; prone to unexpected changes; not consistent. 

noun
  • A rock moved from one location to another, usually by a glacier. 

  • Anything that has erratic characteristics. 

random

adj
  • Being out of the ordinary; unusual or unexpected. 

  • Pseudorandom; mimicking the result of random selection. 

  • Apropos of nothing; lacking context; unexpected; having apparent lack of plan, cause, or reason. 

  • Characterized by or often saying random things; habitually using non sequiturs. 

  • Having unpredictable outcomes and, in the ideal case, all outcomes equally probable; resulting from such selection; lacking statistical correlation. 

  • Of or relating to probability distribution. 

  • Representative and undistinguished; typical and average; selected for no particular reason. 

noun
  • The direction of a rake-vein. 

  • A roving motion; course without definite direction; lack of rule or method; chance. 

  • An undefined, unknown or unimportant person; a person of no consequence. 

  • A frame for composing type. 

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