canid vs domestic dog

canid and domestic dog both are nouns.

Word	Noun	Adjective	Verb	Adverb
canid	Yes	No	No	No
domestic dog	Yes	No	No	No

As nouns, domestic dog is a hyponym of canid; that is, domestic dog is a word with a more specific, narrower meaning than canid:

canid: any of various fissiped mammals with nonretractile claws and typically long muzzles
domestic dog: a member of the genus Canis (probably descended from the common wolf) that has been domesticated by man since prehistoric times; occurs in many breeds

Other hyponyms of canid include bitch, Canis familiaris, dog, wolf, jackal, wild dog, hyaena, hyena, fox.

canid (noun)	domestic dog (noun)
any of various fissiped mammals with nonretractile claws and typically long muzzles	a member of the genus Canis (probably descended from the common wolf) that has been domesticated by man since prehistoric times; occurs in many breeds