Relating to an anatomical isthmus.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
Examples from the Web for isthmic
Historical Examples of isthmic
But the consciousness that the Mexican civilization was affiliated to that of the isthmic region had by no means been lost.