superstring vs particle

superstring and particle both are nouns.

Word	Noun	Adjective	Verb	Adverb
superstring	Yes	No	No	No
particle	Yes	No	No	No

As nouns, particle is a hypernym of superstring; that is, particle is a word with a broader meaning than superstring:

superstring: a hypothetical particle that is the elementary particle in a theory of space-time
particle: a body having finite mass and internal structure but negligible dimensions

Other hypernyms of superstring include subatomic particle.

superstring (noun)	particle (noun)
a hypothetical particle that is the elementary particle in a theory of space-time	a function word that can be used in English to form phrasal verbs
	a body having finite mass and internal structure but negligible dimensions
	(nontechnical usage) a tiny piece of anything