warhorse vs courser

warhorse and courser both are nouns.

Word	Noun	Adjective	Verb	Adverb
warhorse	Yes	No	No	No
courser	Yes	No	No	No

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

Other hyponyms of warhorse include cavalry horse, charger, steed.

warhorse (noun)	courser (noun)
horse used in war	swift-footed terrestrial plover-like bird of southern Asia and Africa; related to the pratincoles
a work of art (composition or drama) that is part of the standard repertory but has become hackneyed from much repetition	formerly a strong swift horse ridden into battle
an experienced person who has been through many battles; someone who has given long service	a dog trained for coursing
	a huntsman who hunts small animals with fast dogs that use sight rather than scent to follow their prey