idleness vs slumber

idleness

noun
  • The state of being idle; inactivity. 

  • Groundlessness; worthlessness; triviality; vanity; frivolity. 

  • The state of being indolent; indolence. 

slumber

noun
  • A state of ignorance or inaction. 

  • The snooze button on an alarm clock. 

  • A very light state of sleep, almost awake. 

verb
  • To be inactive or negligent. 

  • To be in a very light state of sleep, almost awake. 

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