This is the 1340th most frequent French word.
métro
Subway or underground train system.
In this sentence, 'métro' refers to the subway system used for commuting.
Je prends le métro pour aller au travail chaque matin.
I take the metro to go to work every morning.
Here, 'métro' is used to describe the public transportation system specific to a city, in this case, Paris.
Le métro de Paris est l'un des plus anciens du monde.
The Paris metro is one of the oldest in the world.
In this example, 'métro' can better be interpreted as shorthand for a metro pass or card, showing how in informal conversation, objects can sometimes adopt the names of their associated systems.