lower jaw vs mandible

lower jaw and mandible both are nouns.

Word	Noun	Adjective	Verb	Adverb
lower jaw	Yes	No	No	No
mandible	Yes	No	No	No

As nouns, lower jaw and mandible are synonyms defined as:

lower jaw and mandible: the jaw in vertebrates that is hinged to open the mouth

Other synonyms of lower jaw include jawbone, jowl, lower jawbone, mandibula, mandibular bone, submaxilla.

lower jaw (noun)	mandible (noun)
the jaw in vertebrates that is hinged to open the mouth	the jaw in vertebrates that is hinged to open the mouth