gajillion vs gillion

gajillion

noun

  • An unspecified large number (of); a gazillion. 

gillion

noun

  • An unspecified large number (of). 

num

  • A thousand million, proposed as an alternative to the (now little used) British milliard and the (ambiguous, in the UK) US billion. 

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