Wiktionary
megadollar
a. Of a million dollars or more. n. The sum of a million dollars (or any comparably large amount of money).
Usage examples of "megadollar".
I sleep on a narrow, hard bunk bed and dream up scams, but it's so very hard to figure out how to turn a megadollar profit when you're as broke as I am now.
Look at those late twentieth-century megadollar daubs you can't give away now.
On being warned that their data banks would be erased automatically at a certain time, unless they transferred a few megadollars to some anonymous offshore number, most victims decided not to risk possibly irreparable disaster.