Definition of "lower jawbone" []

• The jaw in vertebrates that is hinged to open the mouth (noun)

WordNet. Princeton University. 2010.

• "For those who know A. Bovy's medallion I may add that the early portrait is very like it; only, in the latter, the line formed by the lower jawbone that runs from the chin towards the ear is more rounded, and the whole has a more youthful appearance."