addiction vs feudalism

addiction

noun
  • The state of being addicted; devotion; inclination. 

  • A pathological relationship to mood altering experience that has life damaging consequences. 

  • A habit or practice that damages, jeopardizes or shortens one's life but when ceased causes trauma. 

  • A state that is characterized by compulsive drug use or compulsive engagement in rewarding behavior, despite negative consequences. 

feudalism

noun
  • A social system based on personal ownership of resources and personal fealty between a suzerain (lord) and a vassal (subject). Defining characteristics are direct ownership of resources, personal loyalty, and a hierarchical social structure reinforced by religion. 

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