a secret group organized to overthrow a government or occupation force政府、または、占領軍を崩壊させるために組織された秘密グループレジスタンス
an electric railway operating below the surface of the ground (usually in a city); "in Paris the subway system is called the `metro' and in London it is called the `tube' or the `underground'"地下を走る電車(通常都市で)地下鉄道
conducted with or marked by hidden aims or methods; "clandestine intelligence operations"; "cloak-and-dagger activities behind enemy lines"; "hole-and-corner intrigue"; "secret missions"; "a secret agent"; "secret sales of arms"; "surreptitious mobilization of troops"; "an undercover investigation"; "underground resistance"隠された目的または方法で行われる、あるいは特徴とされる秘密