1
general::
Very many, a large number; also, very much. For example, A lot of people think the economy is declining, or Sad movies always made her cry a lot. It is sometimes put as a whole lot for greater emphasis, as in I learned a whole lot in his class. It may Also emphasize a comparative indication of amount, as in We need a whole lot more pizza to feed everyone, or Mary had a lot less nerve than I expected. [Colloquial; early 1800s]
American Heritage Idioms