railroad line

Từ điển WordNet v3.1 - WordNet Dictionary

noun

line that is the commercial organization responsible for operating a system of transportation for trains that pull passengers or freight
• Syn:
railway, railroad, railway line, railway system
• Derivationally related forms:
railroad (for: railroad)
• Hypernyms:
line
• Hyponyms:
cable railway, funicular, funicular railway, cog railway, rack railway,
elevated railway, elevated railroad, elevated, el, overhead railway, metro,
metro, underground, subway system, subway, monorail,
rail, scenic railway