formal vs obstruent

formal

noun
  • Formalin. 

  • An event with a formal dress code. 

  • 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. 

obstruent

noun
  • Hypernym: consonant 

  • A consonant sound formed by obstructing the airway, causing turbulence; a plosive, fricative, or affricate. 

  • Anything that obstructs, especially in the passages of the body. 

adj
  • Causing obstruction; blocking up. 

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