mule vs equid

mule and equid both are nouns.

Word	Noun	Adjective	Verb	Adverb
mule	Yes	No	No	No
equid	Yes	No	No	No

As nouns, equid is a hypernym of mule; that is, equid is a word with a broader meaning than mule:

mule: hybrid offspring of a male donkey and a female horse; usually sterile
equid: hoofed mammals having slender legs and a flat coat with a narrow mane along the back of the neck

Other hypernyms of mule include equine.

mule (noun)	equid (noun)
hybrid offspring of a male donkey and a female horse; usually sterile	hoofed mammals having slender legs and a flat coat with a narrow mane along the back of the neck
a slipper that has no fitting around the heel