gibberish vs plain English

gibberish

adj
  • unintelligible, incoherent or meaningless 

noun
  • Needlessly obscure or overly technical language. 

  • Speech or writing that is unintelligible, incoherent or meaningless. 

  • A language game, comparable to pig Latin, in which one inserts a nonsense syllable before the first vowel in each syllable of a word. 

plain English

noun
  • English that does not use any jargon or technical / scientific terminology. 

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