noun
diesel fuel; diesel oil; gas oil; light oil
The ordinary word for fuel used in diesel engines. English labels vary by context: in everyday use it is usually 'diesel fuel', while 'gas oil' or 'light oil' may appear in petroleum or regulatory contexts.
ディーゼル車には軽油を入れる。
You put diesel fuel in a diesel vehicle.
間違えて軽油ではなくガソリンを入れてしまった。
I accidentally put in gasoline instead of diesel fuel.