sibilous vs strident

sibilous

adj
  • Having a hissing sound; sibilant. 

strident

adj
  • Loud; shrill, piercing, high-pitched; rough-sounding 

  • Grating or obnoxious 

  • Vigorous; making strides 

noun
  • One of a class of s-like fricatives produced by an airstream directed at the upper teeth. 

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