Sentence:  Businessmen rushed to get every last commodity aboard a departing ship, hoping for a <WSD>windfall</WSD> once the world realized these would be the very last sacks of flour available, thus driving up prices. 
Meaning of the word marked with <WSD> tags:  A sudden large benefit; especially, a sudden or unexpected large amount of money, as from lottery or sweepstakes winnings or an unexpected inheritance or gift.