1. a very large or important business transaction or agreement, typically involving substantial sums of money or significant commercial impact
Usage: informal; business/finance context

Examples

• The tech company announced a megadeal worth $5 billion to acquire its competitor.
• Wall Street analysts are calling this merger a megadeal that will reshape the industry.
• The sports franchise signed a megadeal with a new television network for broadcasting rights.
• After months of negotiations, the two corporations finally closed their megadeal.
• Investors are excited about the potential returns from this megadeal.