tardy vs ultrasonic

tardy

noun
  • A piece of paper given to students who are late to class. 

  • An instance of a student's being marked as tardy by a teacher on the teacher's attendance sheet. 

adj
  • Ineffectual; slow-witted, slow to act, or dull. 

  • Late; overdue or delayed. 

  • Moving with a slow pace or motion; not swift. 

ultrasonic

adj
  • Beyond (higher in frequency than) the range of sound perceptible to the human ear; with a frequency of 20 kilohertz or higher. 

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