el vs railroad line

el and railroad line both are nouns.

Word	Noun	Adjective	Verb	Adverb
el	Yes	No	No	No
railroad line	Yes	No	No	No

As nouns, railroad line is a hypernym of el; that is, railroad line is a word with a broader meaning than el:

el: a railway that is powered by electricity and that runs on a track that is raised above the street level
railroad line: line that is the commercial organization responsible for operating a system of transportation for trains that pull passengers or freight

Other hypernyms of el include railroad, railway, railway line, railway system.

el (noun)	railroad line (noun)
a railway that is powered by electricity and that runs on a track that is raised above the street level	line that is the commercial organization responsible for operating a system of transportation for trains that pull passengers or freight