pacer vs Equus caballus

pacer and Equus caballus both are nouns.

Word	Noun	Adjective	Verb	Adverb
pacer	Yes	No	No	No
Equus caballus	Yes	No	No	No

As nouns, Equus caballus is a hypernym of pacer; that is, Equus caballus is a word with a broader meaning than pacer:

pacer: a horse trained to a special gait in which both feet on one side leave the ground together
Equus caballus: solid-hoofed herbivorous quadruped domesticated since prehistoric times

Other hypernyms of pacer include horse.

pacer (noun)	Equus caballus (noun)
a horse trained to a special gait in which both feet on one side leave the ground together	solid-hoofed herbivorous quadruped domesticated since prehistoric times
a horse used to set the pace in racing