地下铁路

subway

-ly / structural particle: used before a verb or adjective, linking it to preceding modifying adverbial adjunct

earth / ground / field / place / land / CL:片[pian4]

underground / subterranean / covert

down / downwards / below / lower / later / next (week etc) / second (of two parts) / to decline / to go down / to arrive at (a decision, conclusion etc) / measure word to show the frequency of an action

surname Tie

iron (metal) / arms / weapons / hard / strong / violent / unshakeable / determined / close / tight (slang)

railroad / railway / CL:條|条[tiao2]

surname Lu

road / CL:條|条[tiao2] / journey / route / line (bus etc) / sort; kind