1) Craniometric point 
tip of the chin
The most inferior point of the mandible in the midline. In cephalometrics, it is the midpoint between the most anterior and inferior point on the bony chin, measured at the intersection of the mandibular baseline and the nasion-pogonion line. ... Origin: G. Gnathos, jaw ... (05 Mar 2000) ... 
(nath´e-on) the most outward and everted point on the profile curvature of the chin.
Type: Term Pronunciation: nath′ē-on Definitions: 1. The most inferior point of the mandible in the midline. In cephalometrics, it is the midpoint between the most anterior and inferior point on the bony chin, measured at the intersection of the mandibular baseline and the nasion-pogonion line.
The gnathion is the lowest point of the midline of the lower jaw. It is used as a reference point in craniometry.
[n] - the most inferior point of the mandible in the midline
noun the most inferior point of the mandible in the midline
the lowest point on the anterior margin of the lower jaw in the midsaggital plane.