arbitrary vs spontaneous

arbitrary

adj
  • Determined by impulse rather than reason; heavy-handed. 

  • Not representative or symbolic; not iconic. 

  • Determined by independent arbiter. 

  • Based on individual discretion or judgment; not based on any objective distinction, perhaps even made at random. 

  • Any, out of all that are possible. 

noun
  • Anything arbitrary, such as an arithmetical value or a fee. 

spontaneous

adj
  • Arising from a momentary impulse. 

  • Sudden, without warning. 

  • Controlled and directed internally; self-active; spontaneous movement characteristic of living things. 

  • Random. 

  • Done by one's own free choice, or without planning. 

  • Produced without being planted or without human cultivation or labor. 

  • Self-generated; happening without any apparent external cause. 

  • Proceeding from natural feeling or native tendency without external or conscious constraint. 

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