fieldsman vs outfielder

fieldsman and outfielder both are nouns.

Word	Noun	Adjective	Verb	Adverb
fieldsman	Yes	No	No	No
outfielder	Yes	No	No	No

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

fieldsman: a member of the cricket team that is fielding rather than batting
outfielder: a fielder in cricket who is stationed in the outfield

fieldsman (noun)	outfielder (noun)
a member of the cricket team that is fielding rather than batting	(baseball) a person who plays in the outfield
	a fielder in cricket who is stationed in the outfield