obstruent vs synchronous

obstruent

adj
  • Causing obstruction; blocking up. 

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

  • Hypernym: consonant 

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

synchronous

adj
  • Single-threaded; blocking; occurring in the same thread as other computations, thereby preventing those computations from resuming until the communication is complete. 

  • At the same time, at the same frequency. 

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