Where does “Pas-de-Calais” come from?

Pas-de-Calais (English) comes from French Pas de Calais, from French dé, from Middle French de, from Old French dé, from Latin dē, from Latin post, from Latin poste, from Proto-Italic posti — afterwards, post; by, at.

Ancestry of “Pas-de-Calais”, step by step

StepLanguageWordMeaning
1FrenchPas de CalaisDover Strait
2Frenchdie; diced slice; thimble
3Middle Frenchdeof; from
4Old Frenchdie
5Latinof; concerning; about
6Latinpostbehind; after, since, besides, except; behind,...
7Latinposteablative singular of postis
8Proto-Italicpostibehind, after
9Proto-Indo-Europeanpóstiafter
10Proto-Indo-Europeanpósafterwards, post; by, at
Every word from Proto-Indo-European pósEvery word from Proto-Indo-European póstiEvery word from Proto-Italic posti