granule vs plastid

granule and plastid both are nouns.

Word	Noun	Adjective	Verb	Adverb
granule	Yes	No	No	No
plastid	Yes	No	No	No

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

granule: a tiny grain
plastid: any of various small particles in the cytoplasm of the cells of plants and some animals containing pigments or starch or oil or protein

Other hyponyms of granule include microsome, chondrule.

granule (noun)	plastid (noun)
a tiny grain	any of various small particles in the cytoplasm of the cells of plants and some animals containing pigments or starch or oil or protein