steed vs warhorse

steed and warhorse both are nouns.

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

As nouns, warhorse is a hypernym of steed; that is, warhorse is a word with a broader meaning than steed:

steed (noun)	warhorse (noun)
(literary) a spirited horse for state of war	horse used in 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