erratic vs habitual

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. 

habitual

adj
  • Of a person or thing: engaging in some behaviour as a habit or regularly. 

  • Pertaining to an action performed customarily, ordinarily, or usually. 

  • Of or relating to a habit; established as a habit; performed over and over again; recurrent, recurring. 

  • Regular or usual. 

noun
  • One who does something habitually, such as a serial criminal offender. 

  • A construction representing something done habitually. 

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