gruff vs sibilant

gruff

adj
  • hoarse-voiced. 

  • Of goods: bulky. 

  • having a rough, surly, and harsh demeanor and nature. 

verb
  • To speak gruffly. 

sibilant

adj
  • Characterized by a hissing or hushing sound such as the s or sh in sack or shack. 

noun
  • A consonant having a hissing or hushing sound such as the s or sh in sack or shack. 

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