nasal index: Meaning and Definition of

na'sal in'dex

Pronunciation: [key]
  1. (of the skull) the ratio of the distance from nasion to the lower margin of the nasal aperture to that of the maximum breadth of the nasal aperture.
  2. (of the head) the ratio of the maximum breadth of the external nose to its height from the nasal root to where the septum is confluent with the upper lip.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.