grade crossing vs carrefour

grade crossing and carrefour both are nouns.

Word	Noun	Adjective	Verb	Adverb
grade crossing	Yes	No	No	No
carrefour	Yes	No	No	No

As nouns, carrefour is a hypernym of grade crossing; that is, carrefour is a word with a broader meaning than grade crossing:

grade crossing: intersection of a railway and a road on the same level; barriers close road when trains pass
carrefour: a junction where one street or road crosses another

Other hypernyms of grade crossing include crossing, crossroad, crossway, intersection.

grade crossing (noun)	carrefour (noun)
intersection of a railway and a road on the same level; barriers close road when trains pass	a junction where one street or road crosses another