puerile vs sibilous

puerile

adj
  • Childish; trifling; silly. 

  • Characteristic of, or pertaining to, a boy or boys; compare puellile. 

sibilous

adj
  • Having a hissing sound; sibilant. 

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