legging vs long underwear

legging

noun
  • One of the legs of a pair of trousers. 

  • The process of putting a series of three or more options strikes into the stock market. 

  • A covering, usually of leather, worn from knee to ankle. 

  • Tight fitting leg coverings worn, for example, to gym. 

long underwear

noun
  • Two-piece underwear with long legs and long sleeves that is normally worn during cold weather. 

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