lightheadedness vs seasickness

lightheadedness

noun
  • The state or quality of being light-headed; dizziness or faintness; flightiness; wandering; delirium. 

seasickness

noun
  • Nausea, dizziness etc caused by the motion of a ship; a form of motion sickness. 

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