herdsman vs goatherd

herdsman and goatherd both are nouns.

Word	Noun	Adjective	Verb	Adverb
herdsman	Yes	No	No	No
goatherd	Yes	No	No	No

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

Other hyponyms of herdsman include goat herder, sheepherder, sheepman, shepherd, pigman, swineherd.

herdsman (noun)	goatherd (noun)
someone who drives a herd	a person who tends a flock of goats