fretful vs sibilant

fretful

adj

  • Irritable, bad-tempered, grumpy or peevish. 

  • Unable to relax; fidgety or restless. 

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 fretful and sibilant occurred in a corpus of books? (source: Google Ngram Viewer )