digital clock vs timer

digital clock

noun
  • A clock that displays the time (hours, minutes, and sometimes seconds) in digits, rather than by hands on a dial (like a analog clock). 

timer

noun
  • A device used to measure amounts of time. 

  • Any electronic function that causes a device to be able to do something automatically after a preset amount of time. 

  • A person who records the time elapsed in a sporting event. 

  • One who has done something a certain number of times. 

  • One characterized by a certain time or time frame, such as their work hours. 

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