This is the 8055th most frequent Japanese word.
宇部線
The Japanese word "宇部線" (Ube-sen) refers to the "Ube Line," a railway line in Yamaguchi Prefecture, Japan.
In this sentence, '宇部線' refers to a proper noun, the name of a specific railway line.
宇部線は山口県にあるローカル線です。
The Ube Line is a local railway line located in Yamaguchi Prefecture.
Here, '宇部線' is used to describe the means of transportation for the subject's commute.
私は宇部線で通勤しています。
I commute using the Ube Line.
In this example, '宇部線' specifies the location context related to the train line.