gassiness vs periphrasis

gassiness

noun
  • The state or property of being gassy. 

periphrasis

noun
  • Expressing a grammatical meaning (such as a tense) using a syntactic construction rather than morphological marking. 

  • The substitution of a descriptive word or phrase for a proper name (a type of circumlocution). 

  • The use of a longer expression instead of a shorter one with a similar meaning, for example "I am going to" instead of "I will". 

  • The use of a proper name as a shorthand to stand for qualities associated with it. 

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