a flat area for walking on, built across the space between the sides of a boat:
Passengers on the cruise ship gathered on the upper deck to enjoy panoramic views of the ocean.
The stadium's upper deck provides a bird's-eye view of the entire field during sporting events.
The luxury yacht featured a spacious lounge on the upper deck for social gatherings.
Concertgoers in the venue's upper deck had an excellent vantage point for the live performance.
