oyster vs serving

oyster and serving both are nouns.

Word	Noun	Adjective	Verb	Adverb
oyster	Yes	No	Yes	No
serving	Yes	No	No	No

As nouns, serving is a hypernym of oyster; that is, serving is a word with a broader meaning than oyster:

Other hypernyms of oyster include helping, portion.

oyster (noun)	serving (noun)
marine mollusks having a rough irregular shell; found on the sea bed mostly in coastal waters	the act of delivering a writ or summons upon someone
edible body of any of numerous oysters	an individual quantity of food or drink taken as part of a meal
a small muscle on each side of the back of a fowl

oyster (verb)	serving (verb)
gather oysters, dig oysters