tights vs unitard

tights

noun
  • A close-fitting, sheer or non-sheer skin-tight garment worn principally by women and girls that covers the body completely from the waist down, usually including the feet. 

  • A garment, similar to briefs, worn chiefly by professional wrestlers. 

  • In blasting rock, a piece of unbroken rock within the pay limit of a blast. 

  • A similar, non-sheer garment worn by dancers of either sex, especially by ballet dancers. 

unitard

noun
  • A skin-tight garment covering the torso and the legs, sometimes the arms and feet. 

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