Final answer:
The coastal areas around Genoa, Nice, and Acapulco are described with the seven-letter word 'Riviera', a term synonymous with picturesque coastal resort regions.
Step-by-step explanation:
The seven-letter word used to describe the coastal areas surrounding the cities of Genoa, Italy; Nice, France; and Acapulco, Mexico is Riviera. These regions are known for their beautiful coastline and are popular tourist destinations. The term "Riviera" is often associated with high-end resorts and picturesque scenery. For instance, the Italian Riviera includes the area along the Mediterranean coast near Genoa, while the French Riviera, also known as the Côte d'Azur, includes Nice. Acapulco is part of the Mexican Riviera, which sits along the Pacific coast.