B1
a piece of cloth with a special design and colors, that is the symbol of a country or a group, or has a particular meaning
Dictionary examples:
The lazy student's flag design was just a white rectangle. (0.0)
The sleepy town's new flag shows a big pillow and closed eyes. (0.0)
The pirate's flag had a smiley face instead of a skull. (0.0)
Flags of all twenty-seven countries are flying outside the building. (20.9)
Colorful flags decorated the hall. (29.0)
the Brazilian flag (50.9)