This is the 2347th most frequent French word.
plat
Flat; dish; plate.
In this sentence, 'plat' refers to a prepared dish or meal, often a main course in dining.
Ce plat est délicieux.
This dish is delicious.
In this context, 'plat' is used metaphorically as an adjective to describe something as uninteresting or lacking in excitement.
Il a raconté une histoire un peu plate.
He told a story that was somewhat dull.
Here, 'plat' is used as an adjective ('plate') to describe something that is flat or level in physical form.