Strait of Calais vs Pas de Calais

Strait of Calais and Pas de Calais both are nouns.

Word	Noun	Adjective	Verb	Adverb
Strait of Calais	Yes	No	No	No
Pas de Calais	Yes	No	No	No

As nouns, Strait of Calais and Pas de Calais are synonyms defined as:

Strait of Calais and Pas de Calais: the strait between the English Channel and the North Sea; shortest distance between England and the European continent

Other synonyms of Strait of Calais include Strait of Dover.

Strait of Calais (noun)	Pas de Calais (noun)
the strait between the English Channel and the North Sea; shortest distance between England and the European continent	the strait between the English Channel and the North Sea; shortest distance between England and the European continent