warhorse vs steed

warhorse and steed both are nouns.

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

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

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

warhorse (noun)	steed (noun)
horse used in war	(literary) a spirited horse for state of war
a work of art (composition or drama) that is part of the standard repertory but has become hackneyed from much repetition
an experienced person who has been through many battles; someone who has given long service