warhorse vs saddle horse

warhorse and saddle horse both are nouns.

Word	Noun	Adjective	Verb	Adverb
warhorse	Yes	No	No	No
saddle horse	Yes	No	No	No

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

Other hypernyms of warhorse include mount, riding horse.

warhorse (noun)	saddle horse (noun)
horse used in war	a lightweight horse kept for riding only
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