sibilant vs tumultuous

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. 

tumultuous

adj

  • Characterized by loud, confused noise. 

  • Causing or characterized by tumult; chaotic, disorderly, turbulent. 

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