roller coaster vs el

roller coaster and el both are nouns.

Word	Noun	Adjective	Verb	Adverb
roller coaster	Yes	No	No	No
el	Yes	No	No	No

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

roller coaster: elevated railway in an amusement park (usually with sharp curves and steep inclines)
el: a railway that is powered by electricity and that runs on a track that is raised above the street level

Other hypernyms of roller coaster include elevated, elevated railroad, elevated railway, overhead railway, ride.

roller coaster (noun)	el (noun)
elevated railway in an amusement park (usually with sharp curves and steep inclines)	a railway that is powered by electricity and that runs on a track that is raised above the street level
anything characterized by abrupt and extreme changes (especially up and down)