shortstop vs infielder

shortstop and infielder both are nouns.

Word	Noun	Adjective	Verb	Adverb
shortstop	Yes	No	No	No
infielder	Yes	No	No	No

As nouns, infielder is a hypernym of shortstop; that is, infielder is a word with a broader meaning than shortstop:

shortstop (noun)	infielder (noun)
the fielding position of the player on a baseball team who is stationed between second and third base	(baseball) a person who plays a position in the infield
(baseball) the person who plays the shortstop position