onomatopoeia vs understatement

onomatopoeia

noun
  • The property of a word of sounding like what it represents. 

  • The use of language whose sound imitates that which it names. 

  • A word that sounds like what it represents, such as "gurgle," "stutter," or "hiss". 

  • A word that appropriates a sound for another sensation or a perceived nature, such as "thud", "beep", or "meow"; an ideophone, phenomime. 

understatement

noun
  • A figure of speech whereby something is made to seem smaller or less important than it actually is, either through phrasing or lack of emphasis, often for ironic effect. 

  • An incomplete disclosure that intentionally withholds relevant information. 

  • An instance of such phrasing or lack of emphasis. 

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