Metro
来自Big Physics
early 20th century: from French métro, abbreviation of métropolitain (from Chemin de Fer Métropolitain ‘Metropolitan Railway’).
wiktionary
From French métro, clipping of métropolitain (from Ancient Greek μήτηρ(mḗtēr, “mother”) + πόλις(pólis, “city”)), as in the Chemin de fer métropolitain, an early name for the Paris Métro. This name was a direct translation of "Metropolitan Railway", which was the original name of the earliest part of the London Underground, constructed in 1863.
Abbreviation of metropolitan.
etymonline
Metro (n.)
Paris underground, 1904, from French abbreviation of Chemin de Fer Métropolitain "Metropolitan Railway" (see metropolitan (adj.)). French chemin de fer "railroad" is literally "iron road." Construction began in 1898.
