from The American Heritage® Dictionary of the English Language, 4th Edition
- adj. Having a head of medium breadth, with a cephalic index between 76 and 80.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- adj. Having a head that is not particularly short or long from front to back (relative to its width from left to right).
- n. A mesocephalic person.
from the GNU version of the Collaborative International Dictionary of English
- adj. Of or pertaining to, or in the region of, the middle of the head.
- adj. Having the cranial cavity of medium capacity; neither megacephalic nor microcephalic.
- adj. Having the ratio of the length to the breadth of the cranium a medium one; mesaticephalic.
from The Century Dictionary and Cyclopedia
- In craniometry, of medium size; neither large nor small; with a capacity of from 1,350 to 1,450 cubic centimeters.
- Having a skull of medium breadth or capacity.
- Of or relating to the mesencephalon.
From meso- + cephalic, hence literally roughly “medium-headed”. (Wiktionary)