meteor vs meteor swarm

meteor and meteor swarm both are nouns.

Word	Noun	Adjective	Verb	Adverb
meteor	Yes	No	No	No
meteor swarm	Yes	No	No	No

As nouns, meteor swarm is a hyponym of meteor; that is, meteor swarm is a word with a more specific, narrower meaning than meteor:

meteor: (astronomy) any of the small solid extraterrestrial bodies that hits the earth's atmosphere
meteor swarm: a group of meteoroids with similar paths

Other hyponyms of meteor include meteorite.

meteor (noun)	meteor swarm (noun)
(astronomy) any of the small solid extraterrestrial bodies that hits the earth's atmosphere	a group of meteoroids with similar paths
a streak of light in the sky at night that results when a meteoroid hits the earth's atmosphere and air friction causes the meteoroid to melt or vaporize or explode