formal vs white tie

formal

noun
  • An event with a formal dress code. 

  • Formalin. 

  • A formal parameter. 

  • An evening gown. 

  • An acetal formed from formaldehyde. 

adj
  • Official. 

  • Relating to mere manipulation and construction of strings of symbols, without regard to their meaning. 

  • Relating to formation. 

  • Organized; well-structured and planned. 

  • Being in accord with established forms. 

  • Relating to the form or structure of something. 

  • Ceremonial or traditional. 

  • Proper, according to strict etiquette; not casual. 

white tie

noun
  • A dress code specifying white tie for men and ball gown or evening dress for women, or, alternatively, full military dress or national costume. 

  • The most formal kind of eveningwear for men, consisting of an evening tailcoat, trousers with strips of braid down the side seams, white stiff-fronted shirt, white bow tie and waistcoat with or without sash. 

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