dinner dress vs formal

dinner dress

noun
  • A gown worn by Victorian women for dinners and parties held in people's homes. It often had long sleeves, a high neck, or a narrow skirt to set it apart from an evening gown. 

formal

noun
  • An evening gown. 

  • An event with a formal dress code. 

  • Formalin. 

  • A formal parameter. 

  • 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. 

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