mentomeckelian

from The Century Dictionary.

• noun A distal division of Meckel's cartilage around which the lower jaw ossifies, as distinguished from a proximal division which is converted into a part of the suspensorium of the jaw or an ossicle of the ear.

from the GNU version of the Collaborative International Dictionary of English.

• adjective (Anat.) Of or pertaining to the chin and lower jaw.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• adjective anatomy Of or relating to the chin and lower jaw.
• noun anatomy The bone or cartilage forming the anterior extremity of the lower jaw in some animals.