sleepiness vs slumber

sleepiness

noun

  • The property of being sleepy. 

slumber

noun

  • A very light state of sleep, almost awake. 

  • A state of ignorance or inaction. 

  • The snooze button on an alarm clock. 

verb

  • To be inactive or negligent. 

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

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