WHOLE SLEW OF can be defined as a large amount or quantity of something. This phrase is often used to describe a large number of people or things. The two crossword solutions for this phrase are ZILLION (7 letters) and LOTTA (5 letters). ZILLION is an informal term used to describe an extremely large number, while LOTTA is an informal term used to describe a large number. Both terms are used to emphasize the large amount or quantity of something.