Ginormous number is a term used to describe an extremely large number that is too big to be counted. The crossword solutions for this term are Zillion (7 letters), BILLIONS (8 letters), and UMPTEEN (7 letters). Zillion is an informal term used to describe an extremely large, but unspecified number. BILLIONS is a term used to describe a thousand million or 1, 000, 000, 000. UMPTEEN is an informal term used to describe a large, but unspecified number.