herdsman vs shepherd

herdsman and shepherd both are nouns.

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

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

herdsman: someone who drives a herd
shepherd: a herder of sheep (on an open range); someone who keeps the sheep together in a flock

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

herdsman (noun)	shepherd (noun)
someone who drives a herd	a herder of sheep (on an open range); someone who keeps the sheep together in a flock
	a clergyman who watches over a group of people

herdsman (verb)	shepherd (verb)
	tend as a shepherd, as of sheep or goats
	watch over like a shepherd, as a teacher of her pupils