This is the 2298th most frequent French word.
massif
A large mountain or group of connected mountains.
Here, "massif" is used as a noun to refer to a mountain mass or a group of connected mountains.
Le massif montagneux est couvert de neige.
The mountain massif is covered in snow.
Here, "massif" is used as an adjective meaning "massive," describing the size or bulkiness of the coat.
Il porte un manteau massif pour se protéger du froid.
He is wearing a massive coat to protect himself from the cold.
In this sentence, "massif" is used as an adjective meaning "substantial or significant," referring to the scale of the impact.