baby tooth vs primary tooth

baby tooth and primary tooth both are nouns.

Word	Noun	Adjective	Verb	Adverb
baby tooth	Yes	No	No	No
primary tooth	Yes	No	No	No

As nouns, baby tooth and primary tooth are synonyms defined as:

baby tooth and primary tooth: one of the first temporary teeth of a young mammal (one of 20 in children)

Other synonyms of baby tooth include deciduous tooth, milk tooth.

baby tooth (noun)	primary tooth (noun)
one of the first temporary teeth of a young mammal (one of 20 in children)	one of the first temporary teeth of a young mammal (one of 20 in children)