neglect vs observance

neglect

verb
  • To fail to do or carry out something due to oversight or carelessness. 

  • To fail to care for or attend to something. 

  • To omit to notice; to forbear to treat with attention or respect; to slight. 

  • To ignore for the sake of simplifying calculations without significantly affecting accuracy. 

noun
  • Habitual lack of care. 

  • The act of neglecting. 

  • The state of being neglected. 

observance

noun
  • The practice of complying with a law, custom, command or rule. 

  • That which is to be observed. 

  • Observation or the act of watching. 

  • A rule governing a religious order, especially in the Roman Catholic church. 

  • The custom of celebrating a holiday or similar occasion. 

  • Reverence; homage. 

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